astronomy final
describe the shape of comet 67p
appears to be result of collision of 2 previously separate nuclei
what's the difference between archaea and bacteria?
archaea has more complex rna polymerases than bacteria but are otherwise fairly similar
describe the two strands making up dna
are complimentary to each other - means that sequences of bases in one strand can be used to create correct sequences of bases in other strand
what generates visible light and other radiation?
atomic-level processes
why can't gas redden starlight?
atomic/molecular gas is transparent while interstellar cloud particles are solid
what is adhesion?
attraction between water molecules and other molecules due to its cohesive forces
describe water's cohesive forces
attraction of water molecules due to hydrogen bonding that keeps molecules together at the point where liquid water meets air - called surface tension
what is a strong nuclear force?
attractive force stronger than electrical forces
describe venus' rotation
backwards and slow - a day on venus is 243 days
what are the domains of life?
bacteria, archaea, eukarya
what are the three domains of the tree of life?
bacteria, archaea, eukarya
what is the definition of a star?
ball of gas capable of getting core hot enough to initiate hydrogen fusion
what are visual binary stars?
binaries close enough to be visible from earth
what are the most common star systems?
binary or triple
why is an iron atom the most stable element?
binding energy is greatest for atoms with a mass closest to that of an iron nucleus
what is cyanobacteria?
blue/green algae that began to produce O2 2.7 billion years ago
what is an ionic bond?
bond between ions
describe the shape of an alpha helix protein
bonds between every 4th amino acid create a twist and subsequent helix in the amino acid chain
describe mars' permanent/residual polar caps
carbon dioxide deposits and water ice
what elements are humans mainly made up of?
carbon, hydrogen, oxygen, nitrogen
what elements are in enceladus' geyser plumes?
carbon, hydrogen, oxygen, nitrogen
what are the reactions called of stars hotter than the sun?
carbon-nitrogen-oxygen cycle
what are the main biological functional groups?
carboxyl, hydroxyl, amino, phosphate
what is the general function of nucleic acids?
carry cell's genetic blueprint
compare prokaryotic chromosomes to eukaryotic chromosomes
circular molecule with less extensive coiling structure than that of eukaryotes
how would binary/multiple star systems affect solar system formation?
circumstellar disc may have trouble forming; some stable orbits might exist but long-term stability would be problematic
how will our habitable zone change in the future?
conservative assumptions state that earth will leave habitable zone when sun is a bit over 5 billion years old
why must dna replicate before a cell divides?
dna needs to be read in order for its encoded molecules to be reproduced; when cells divide, daughter cell must receive identical copy of dna
describe the appearance of prokaryotes
dna not enclosed; cells are a much smaller, single organelle
summarize the dna replication process
dna replication is catalyzed by enzymes; helicase unwinds double helix - separates the two strands by breaking the hydrogen bonds then prepares the strands for base pairing; dna polymerase assembles new base pairs
where are phosphates found?
dna, rna, atp, phospholipids
how do blackbody objects react to radiation?
do not reflect or scatter radiation but instead absorb it
describe the standard luminosities of stars
does not exist; stars have no standard/intrinsic brightness regardless of their location
what does the earth being differentiated tell scientists about its previous state?
earth was once warm enough for its interior to melt, permitting heavier metals to sink to the center and form a dense core
how does dna polymerase prevent itself from making mistakes?
edits dna by proofreading every newly-added base; incorrect bases are removed and replaced by correct base
what is gravitational lensing?
effect predicted by einstein's general theory of relativity that occurs when one object's gravity bends and focuses light/photons of a more distant object
what is the main limiting factor of evolution?
efficiency needs of organisms
list some incorrect theories about where the sun's energy came from
either chemical reactions or gravitational collapse - however, chemical burning would run out in 100 million years and the conversion of gravitational potential energy into heat as sun contracts would only keep the sun shining for 25 million years, and 19th century radioactive dating indicates that the sun is older than that
what are the two types of textures that interstellar dust particles can have?
either sootlike/rich in carbon or sandlike/containing silicon and oxygen
if martian gullies are releasing water, where do scientists think that the water is coming from?
either springs or aquifers
what do all atoms contain?
electric charges
what do changing magnetic fields produce?
electric currents
what type of fields do stationary electric charges produce?
electric fields
how are atoms held together?
electromagnetic force since their opposite charges attract
what determines how elements interact with each other?
electron arrangement
why is an atom not similar to a solar system?
electrons don't orbit an atom's nucleus - they're smeared out in an electron cloud
what is electron ground state?
electrons with lowest energy possible
what is electron excited state?
electrons with more energy than when at ground state
what makes an object magnetic?
electrons' motion alligns
what is an isotope?
element with same number of protons but different number of neutrons
what are elliptical galaxies?
ellipsoid (squashed sphere) or sphere shaped; don't rotate systematically
what are dwarf ellipticals/dwarf spheroidals?
elliptical galaxies but smaller; faint and hard to see thus took awhile to be discovered; have low luminosity
what are telomeres?
ends of linear chromosomes
what is hubble time?
amount of time since beginning of the universe's expansion *assuming* that it has always expanded at the same constant rate
what are eclipsing binaries?
orbital planes entering our line of sight, causing dips in light curve; eclipse durations can give us accurate size of stars and other objects
what causes hot jupiters?
orbiting planet nudges particles of gas into a disk, causing the material to bunch up; the dense regions in the upper atmosphere tug on the planet, causing them to migrate outwards toward sun and into bunched up material
describe the rate of oxygen concentration growth on earth
oxidation reactions in the atmosphere was removing O2 as often as it was being produced, so O2 concentration increased slowly
what happens when a carbon core is exhausted and has become an oxygen core in a star?
oxygen fuses into neon, neon fuses into magnesium, magnesium fuses into sulfur, sulfur fuses into iron
what is a complex sugar made up of?
oxygen linked between two glucose monomers
describe the typical formation of saturated fats
pack tightly together and are solid at room temperature
what is a photon?
particle of electromagnetic energy
how were planets built around the sun?
particles were originally orbiting the sun in the same direction at nearly the same speed, meaning collisions weren't violent; particles began to combine with each other through electrostatic forces since the gravity between them was too weak at this point; as the particles kept combining and growing, gravity began to help the process and turn the particles into planetesimals; same planetesimals continued to grow in size over millions of years; only largest planetesimals survived and weren't shattered by other objects in space; those surviving large planetesimals became planets
describe the distribution of gas and dust in space
patchy and irregular
what is dispersion?
path of light being refracted in a way that not all colors are bent by the same amount - as a result, different wavelengths/colors are bent by different amounts, thus causing light to refract as a rainbow
list the current mars rover missions
pathfinder, spirit, opportunity, phoenix, curiosity
what are microwaves?
photons interfered with by free electrons in the early stages of the universe
what is momentum?
quantification of the difficulty of changing an object's motion
what is angular momentum?
quantity of angular motion
what does the wide possibility of answers to the drake equation indicate?
question of whether extraterrestrial life exists can only be resolved after collecting more data
how fast do larger stars burn fuel?
quickly
what is a possible strategy to predicting solar flares?
relate changes in appearance of small active regions and changes in the sun's local magnetic fields to subsequent flares
what creates genetic code?
relationship between nucleotide codon and its corresponding amino acid
what is a regular orbit for a moon?
revolving around parent planet in west-to-east direction in plane of planet's equator
what does rna stand for?
ribonucleic acid
what's the difference between ribose and deoxyribose molecules?
ribose has one more OH than deoxyribose
what is rrna?
ribosomal rna - structural component of ribosomes; constructs protein from mrna template
describe the makeup of atp
right side has three identical phosphate groups
what do the rings of saturn and uranus have in common?
rings are so close to each other that they behave like water - have ripples and waves
what does the rise of echo-location correlate with?
rise of intelligence
what is the key precursor to the cambrian explosion?
rise of oxygen
describe the dna elongation process
rna polymerase tracks along dna template, synthesizing mrna in a 5' to 3' direction; proteins are stabilized with a nucleotide "cap" on 5' end
describe the likely genetic code of early life on earth
rna-based, since rna can catalyze its own replication without the complicated assistance that dna needs
what is an atom?
smallest unit of matter
what do layered deposits around mars' polar caps tell us?
tell us that there's some sort of cyclic process depositing dust and ice over periods of time
what type of primitive species did humans evolve from?
tree-dwelling animals that developed binocular vision and opposable digits; we lost those tree dwelling abilities when orangutans began to appear
what form must lipids be in to be stored?
triglyceride
what sequence in dna determines the sequence of complement rna?
triplet base sequence
which atomic element typically takes the longest to decay?
uranium-238 - takes 4.47 billion years to decay one half life into lead-206
what is the most common half-life decay?
uranium0238 becomes lead-206
what are the ice giants of our solar system?
uranus and neptune
which of our solar system's planets have attributes of the most common planets in the universe?
uranus and neptune
what are hydrogen bonds?
weak bond between two molecules resulting from electrostatic attraction - a polar molecule's positive side attracts to another polar molecule's negative side
what are ionic bonds?
weak bonds formed when one atom gives up an electron to another atom; opposite charged atoms attract
what do the majority of x-rays from the sun become before reaching earth?
weaken into visible light
what are van der waals interactions?
weakest chemical bond; is a weak attraction/interaction between molecules
what controls the ocean's chemistry?
weather and by-products of land runoff
where did chloroplasts come from?
were originally bacteria that was ingested by ancient cells
what do processed meteorites tell scientists about?
what insides of asteroids are like
what is the zeeman effect?
when a narrow spectral line from an electron changing levels becomes a series of closely placed lines due to the presence of a strong magnetic field
what is a planetary transit?
when a planet crosses in front of a star, causing it to dim slightly
what is a covalent bond?
when an electron is shared between two elements
what is newton's 3rd law?
when an object exerts a force on another object, that other object exerts an equal and opposite force on that first object; because these forces are on different objects, the forces don't necessarily cancel out, but total momentum is still conserved
what are ions?
when atoms lose or gain electrons
what is an ionic attraction?
when atoms' ions are attracted to each other for being oppositely charged; the resulting attraction causes compound formation
what is a transit?
when exoplanet orbit is edge-on to us so that the planet appears to pass in front of its star
when do ice ages occur?
when global average temperatures drop by a few degrees celsius
what is the strongest confirmation method of exoplanets?
when ground-based telescopes can identify major doppler shifts
when are hot jupiters' periodic movements easiest to observe?
when hot jupiters are close to sun
what is an eclipse?
when planet goes behind a star
how do rocks escape mars?
when planet is impacted by asteroids, fragments blast out of its atmosphere
what is synchronous rotation?
when rotation period of a moon/planet/star equals the orbital period around another object
how can dopplar shifts be used to detect orbits?
when viewing stars on a horizontal plane, like they're on a table in front of you, their orbits are detected in redshifts and blueshifts; those dopplar shifts and their length can indicate the length of orbits in specific directions
what is a habitable zone?
where a planet's orbit is right distance away from star and its brightness so that it allows temperatures for liquid water to exist
what are van allen belts?
where dangerous energetic charged particles from solar flares are trapped
what types of questions do scientists asks when looking for other life forms?
where do planets come from? do other planetary systems exist? how do we find other planetary systems?
what is magnetism?
force of charges in motion
what is transcription?
process of making mrna from dna
how much carbon dioxide to plants and photosynthesis absorb per year?
10^11 tons
how many units from base is a mega?
10^6
what is ℵ?
10e+35; strength of forces between atoms/force of gravity between atoms
how does dark matter affect mass-to-light ratios?
always increases it
what was the first spacecraft to visit mars?
america's mariner 4 in 1965
where are aminos found?
amino acids and proteins
which electron shell do elements always want filled first?
outermost shell
how many planet candidates did kepler detect in its lifetime?
over 4000
what is hydrogen fusion?
process of transforming 4 protons into a helium-4 nucleus
what are trans-neptunian objects?
smaller worlds orbiting the sun beyond neptune
what is the basic structure of an amino acid?
amino group, carboxyl group, R group held together by a carbon
what is the majority of jupiter's atmosphere made of?
ammonia
why does saturn appear less colorful than jupiter?
ammonia clouds are deeper on saturn - its cloud layers start later
what causes friction between earth and the moon?
conflict between moon's pull and earth's rotation
how can we determine the rotational rate of jupiter's atmosphere?
distinct details in its cloud patterns
what is the unifying theory of biology?
diversity of life on earth is the result of evolution
what is the central dogma?
dna is transcribed into rna, which is transcribed into protein
why won't all stars actually be infinitely bright?
foreground stars can block some light from other stars
what is a starch?
form of carbohydrate storage in many plants
what is a glycogen?
form of carbohydrate storage4 in many animals
what are structural proteins?
form scaffolding and structure of cells/tissue
what are disaccharides?
form when 2 monosaccharides undergo a dehydration reaction
how does protein synthesis begin?
formation of an initiation complex that interacts with a start codon
compare the transcription processes of prokaryotes and eukaryotes
fundamentally the same
how much hydrogen must be converted into helium per second to produce the sun's luminosity?
600 million tons of hydrogen
what is the surface temperature of the sun?
6000 degrees celsius
how many known moons does saturn have?
62
what is the best current estimate of hubble time?
13.5 billion years, give or take .5 billion
how many moons does neptune have?
14
what would a change in ε most heavily effect?
process of transforming hydrogen into the rest of the periodic table
what influences the form of saturn's rings?
pull of saturn's moon
what's the maximum size a planet can be before being considered too big to be a planet?
14 times the mass of jupiter - .013 solar mass
what is the total mass of gas and dust in the milky way equal to?
15% of mass in most stars
what is Q?
ratio of 2 fundamental energies making up fabric of universe
what would happen to stars if ε was smaller?
stars would have shorter lifespan
how many possible genetic code combinations exist?
64
when did the dinosaurs go extinct?
65 million years ago
how many known moons does jupiter have?
67
what are compounds?
substances in which atoms of two or more elements are chemically combined
what are buffers?
substances that minimizes pH changes - absorb excess hydrogfen ions and hydroxide ions
what are acids?
substances yielding H+ ions/protons
what percentage of earth's organisms are made of carbon?
18%-50%
what is D?
3; number of special dimensions in our world
what is the tertiary structure of a protein?
3D folded polypeptide chains in which fold determines function
how much hydrogen is needed in the proton-proton chain?
6 hydrogens total are inputted during the 1st two steps of the proton-proton chain
what is pluto's surface temperature?
-220 degrees celsius - colder than liquid air
what percentage of the total mass of the solar system do the moons and rings make up?
.00005%
what is ε?
.007; firmness of nuclei bound together
what percentage of the earth's atmosphere is made up of carbon?
.01%
how much mass is lost in the process of producing energy in the sun's nuclear reactions?
.02862 u - .71% of mass of initial hydrogen
what percentage of the total mass of the solar system do all dwarf planets and planets other than jupiter make up?
.04%
what percentage of the earth's crust is made up of carbon?
.05%
what percentage of the total mass of the solar system does jupiter make up?
.1%
what is mars' mass compared to earth's?
.11x the size of earth
how many years after the earth formed did life arise on it?
.5-.8 billion years
what is the pH of the most acidic of substances?
0
describe the pH scale
0-6=acid, 7=neutral, 8-14=base
how many electrons does hydrogen need to fill its shell?
1
how many electrons does sodium need to lose to fill its outer shell?
1
what is earth's atmospheric pressure?
1 bar
what is the mass of visible portions of spiral galaxies?
1 billion to 1 trillion stars
how many asteroid impacts would be enough to account for the amount of water earth has today?
1 every thousand years during earth's 1st billion years
what is the explosion rate of supernovas?
1 per 100 years somewhere in the galaxy
when was the strong nuclear force able to exist?
1 second after the big bang
describe the angular momentum of electrons orbiting at the 2nd lowest energy level
1 unit of momentum with 3 possible orientations
what has the L of the milky way been estimated to be?
1000 - results in final answer of 1 - us
how many 1 km-sized objects currently cross earth's orbit?
1000-3000
what is jupiter's mean density?
1.3 g/cc - similar composition to sun
what is the average density of the sun?
1.4 g/cm^3
how large are super earths?
1.4x-2.8x radius of earth
how far away from the sun is mars?
1.5 au
when did the first eukaryotes evolve into existence?
1.5 billion years ago
how much further away from the sun is the earth during the summer?
1.5% - however this slight ellipticity of earth's orbit isn't what causes seasons; it's only the tilt
what is the distance of the sun?
1.5e+8 km
what is the mass of the sun?
1.9891e+30 kg
what is the potential temperature range of hydrogen gas in space?
100K - 8000K; can rarely reach 1 million degrees
what is the diameter of mars compared to earth's?
1/2 diameter of earth
what portion of the solar system's moons are in regular orbits?
1/3
how many degrees is 1 second of arc orbit equal to?
1/3600 degrees
what is total power per unit surface proportional to?
1/R^2; 1/distance
what is the pH of the most basic of substances?
10
what is the size of the asteroid that killed the dinosaurs?
10 km across
describe the oxygen levels of earth during the cambrian explosion
10% of present levels
what was the universe like 1 second after the big bang?
100 billion degrees celsius hotter than a supernova's center, causing nuclear fusion reactions to take place throughout the entire universe that resulted in a brief synthesis of some elements; these reactions were incredibly brief and ended after 1st 3 minutes of big bang
when did edwin hubble live?
1889-1953
when were brown dwarves and exoplanets discovered?
1995
when and how was the first exoplanet found?
1995 using the doppler effect
what is the ratio of carbon to hydrogen to oxygen in carbohydrate molecules?
1:2:1
what was mars pathfinder?
1st extraterrestrial mission to utilize a rover; launched in 1997 and still operates today
who was vesto m slipher?
1st person to incorrectly assume that the universe is expanding away from earth - hubble had only assumed that the more distant a galaxy is, the faster it's receding from us
how many electrons does the first atomic energy level hold?
2
how many possible directions can electrons spin in?
2
what is the maximum quantity of electrons in an atom's inner shell?
2
when did oxygen begin to build up in the atmosphere?
2 billion years ago
what are binary stars?
2 stars orbiting each other around their common center of mass
describe the angular momentum of electrons orbiting at the 3rd lowest energy level
2 units of momentum
when did oxygen production first begin on earth?
2.7 billion years ago
how large are mini neptunes?
2.8x-4x radius of earth
when was the trappist-1 system found? what found it?
2/22/17 - spitzer telescope
when was the nearest supernova discovered in modern time?
2/24/1987
how many amino acids does life use to form all proteins?
20 even though we know that roughly 70 amino acids exist since nature allows for mirrored versions
how much of the milky way's total gas mass comes from molecular clouds?
20%-30%
what is the average diameter range of a spiral galaxy?
20,000 to over 100,000 lightyears
when did the most recent solar maximum take place?
2014
what is the most productive study of a comet?
2015 rosetta mission by the european space agency
how many moons does uranus have?
27
what is the surface temperature of mercury on its sunlit side?
280-430 degrees celsius
what is the mass of the sun?
2e+30 kg
how many transits must occur before an exoplanet's existence can be confirmed?
3 - since false transits are easy to detect
what is the density of the moon?
3.3 g/cc
when did cyanobacteria begin to release oxygen?
3.5 billion years ago
what is the speed of light?
300 million m/s
how many earths could be made using jupiter's mass?
318
how many electrons does carbon need to fill its shell?
4
what make up the interior of dna?
4 different nitrogenous bases/nucleotides - adenine, cytosine, thymine, guanine
what is the central element of steroids?
4 interlocked carbon rings whose side chains determine steroid type
what is the surface area of a sphere/planet?
4*pi*r^2
how much mass comes out of the hydrogen fusion process?
4.002 amus
how much mass goes into the hydrogen fusion process?
4.032 amus
when did oceans form on earth?
4.4 billion years ago
when did the formation of the moon occur?
4.527 billion years ago, give or take .01 billion years
how many years ago did earth form?
4.543 billion years
how old is the solar system?
4.57 billion years
what's mars' gravity like compared to earth's?
40% less than earth's
what is io's orbital period?
42 hours
how much energy does jupiter emit?
4e+17 watts
what is the sun's luminosity?
4e+26 watts = 4e+26 J
describe jupiter's atmosphere?
500 miles thick, largely made of H2, He, CH4, NH3, water
how many .5 km-sized objects currently cross earth's orbit?
5000-20,000
describe the air pressure under jupiter's atmosphere
500x earth's airpressure
what star does the first exoplanet ever found orbit?
51 pegasi b
what was the first true exoplanet discovered called?
51-pegasus
when did the cambrian explosion occur?
542 million years ago through 500 million years ago
what is the total mass of earth's atmosphere?
5e+8 kg
what is the surface temperature of io?
700 degrees fahrenheit near volcanoes and -250 degrees away from them
what is the radius of the sun?
7e+5 km
what's the maximum quantity of electrons in an atom's second shell?
8
what's the maximum quantity of electrons in an atom's third shell?
8
how many volcanoes did voyager see on io?
8+
how many years does uranus take to orbit the sun?
84
how many spacecraft have gone beyond the solar system's asteroid belt?
8; 7 from us, 1 from europe
what do the oldest star clusters primarily consist of?
90% hydrogen and 10% helium
how many varieties do atoms exist in?
92 - as seen on periodic table
what is uranus' tilt and why?
98 degrees - we don't know why
what percentage of the total mass of the solar system does the sun make up?
99.8%
what is the chemical formula for glucose?
C6 H12 O6
how can the energy released during the sun's nuclear reactions be calculated?
E=mc^2
what is the formula for einstein's theory of relativity?
E=mc^2 where e=energy in joules, m=mass in kg, c=speed of light
list some subcategories of radio waves
FM, AM, TV, radar waves
what makes humans the most evolved species on earth?
we're the only animals to have created a technical civilization
what is the drake equation for the milky way?
N = .001*L
what is the drake equation?
N=star formation rate*number of habitable planets*number of habitable planets that actually have life*number of habitable planets that have intelligent life*number of habitable planets with intelligent, technologically advanced life*average lifetime of a technical civilization
what are indicators of life on other planets??
O3 - ozone - produced by planets/algae; liquid water; methane produced by living organisms; spectrum indicating atmospheric presence of water, ozone, carbon dioxide, nitrogen
what is archaea?
a bacteria - most primitive form of life on earth; is a chemoautotroph; likely dominated early earth when environments were extreme
how much warning does simply observing a solar flare afford astronomers before its affects are felt on earth?
a few days
what is he average speed of winds on mars?
a few kilometers per hour with the occasional windstorm
what is radiation?
a general term for waves radiating outward from a source
how do phospholipids assist in forming cell walls?
a layer of phospholipids can make up half a layer of a cell wall, while two layers combine in a hydrophilic-hydrophobic-hydrophilic orientation to form a full cell wall
which dna nucleotides bond with each other?
a links to t, g links to c
what is plasma?
a hot ionized gas
how did the formation of the moon occur?
a mars-sized plantesimal crashed into the young earth, shattering plantesimal and earth; core of plantesimal then sank within the earth, speeding up it's rotation; moon rocks are therefore similar to earth's
what type of galaxies does the planetary nebulae distance measurement technique work with?
all
what type of galaxies does the redshift/hubble's law distance measurement technique work with?
all
what are saturn's three brightest rings?
a, b, c rings; b ring is brightest and makes up majority of saturns' rings' mass
what percentage of the universe is made up of heavy elements?
about .1%
when were the first stars formed?
about 10 billion years ago
where is the nearest outpost of hypothesized intelligent life located?
about 100 light years away
what type of galaxies does the type Ia supernovae distance measurement technique work with?
all
roughly how many planetary systems have been found so far?
about 2600
when will the sun run out of energy?
about 5 billion years
when did modern apes begin to walk the earth?
about 7 million years ago
how wide are saturn's rings?
about 70,000km
on average, how many years are between a major impact on earth?
about 90 million years
how much of mars' terrain is heavily cratered?
about half of its surface
why is water good for life?
absorbs heat and is very cohesive
what event in 1967 supported the big bang theory?
accidental detection by scientists penzias and wilson of the cosmic microwave background - those radio waves are left over from the big bang
what is accretion?
accumulation of particles into a massive body
what does hubble's constant prevent us from doing?
accurately calculating distance, since it doesn't take into account the acceleration of the universe's expansion
what is the significance of the cambrian explosion?
all 36 modern phyla/body plants appeared - no new phyla have emerged since
what type of energy is dependent on strong interactions?
amount of energy released when simple atoms undergo nuclear fusion
what is Ω?
amount of material in the universe
describe the surface of cassini
active and geologically young
what does the atmospheric composition of titan indicate?
active chemistry where sunlight interacts with atmospheric nitrogen and methane to create a rich mix of organic molecules
what is rna?
active in synthesis of proteins
what is olber's paradox?
adding together the brightness of every star in the universe will result in infinite total brightness, which theoretically should mean that every star should be as bright as the sun
what affects the shape of carbon molecules?
addition of other elements/functional groups; double vs single bonds
what is the dna polymerase?
adds new nucleotides to new dna
which of the nitrogenous bases are two ringed purines?
adenine and guanine
what are the complementary base pairs for dna's four nucleotides?
adenine+thymine and cytosine+guanine
what are the four nucleotides of dna?
adenine, guanine, cytosine, thymine
what are the types of dna nucleotides?
adenine, guanine, cytosine, thymine
what are the four nucleotides of rna?
adenine, guanine, cytosine, uracil
what does atp stand for?
adenosine triphosphate
what's the difference between atp and adp?
adp has one less phosphate group than atp
where did modern humans come from?
africa
when did scientists have an accurate method of measuring the age of the moon?
after astronauts brought moon rocks to earth
when did the direct detection of hydrogen in interstellar clouds occur?
after creation of telescopes - specifically radiotelescopes - capable of seeing low energy changes in hydrogen
when did animals begin to move to land?
after plants moved to land
how can we determine when solar system formation began?
aging primitive meteorites
what is coronal mass ejection?
aka cme; when massive quantities of coronal material - mainly protons and electrons - are ejected at high speeds into space
what is an encephalization quotient?
aka eq; ratio of brain mass to body mass - typically a good indicator of intelligence
what is a spectroscopic binary?
aka spatial binary; can be used to detect binary stars by inferring from 2 doppler shifts of lines; doppler lines are doubled and continually shifting when looking at two orbiting stars
where is hydroxyl found?
alcohols and sugars/carbohydrates
if extraterrestrial optimists were right, what should have happened by now?
aliens should've found us, unless they've already arrived and we don't know it
how are wavelength and frequency related?
all electromagnetic waves travel at the same speed, so, for any wave motion, the speed at which a wave moves equals wave frequency multiplied by wavelength
describe the rings of the jovian planets
all have rings but only saturn's are visible
why do comets always appear bright to us?
all of its water vaporizes as it nears the sun
how does oxygen usually present itself in space?
all oxygen present is usually combined with hydrogen
what are transport proteins?
allow passage of hydrophilic substances across cellular membranes
when did nucleic acids appear on earth?
almost immediately as life developed
how much gas and dust do elliptical galaxies have?
almost no dust and little gas
describe the mass of electrons
almost nothing - if anything, electrons are practically waves
which star systems are closest to us?
alpha centauri and proxima centauri
describe the surface of ganymede
also filled with impact craters but is differentiated; younger terrain was created by tectonics and volcanoes; has continuing geological activity likely due to jupiter's gravity
why do scientists believe that humans were an evolutionary accident?
although intelligence offers some evolutionary advantage, there hasn't been a steady march towards bigger brains - humans might've been an evolutionary accident
how do we know that giant planets have cores composed of heavier materials?
analyses of gravitational fields
how do scientists determine that martian meteorites are indeed from mars?
analyze tiny gas bubbles trapped in them to see if they match mars' atmospheric properties
what is a positron?
antimatter electron
what are vestigial structures?
any body part with no apparent function - is typically reduced in size
what are organic molecules?
any chemical containing carbon
where can convection currents be found?
any dense gas, air, even rock that experiences large changes in temperature
what are the most stable elements?
any elements with electrons fully occupying 1st and 2nd shells - noble gases
what is an irregular galaxy?
any galaxy that isn't elliptical, spiral, or barred spiral shaped
what is an exoplanet?
any planet found outside of our solar system
what is a meteorite?
any remains of a meteor that successfully survived earth's atmosphere
what is a meteor?
any rock/random object capable of hitting earth
when does gene expression regulation occur in eukaryotes?
any time - at all stages of protein synthesis process
according to quantum mechanics, how are waves and particles related?
anything with properties of a wave also has the properties of a particle
what do the microbes in the human body do?
are in our intestines - provides important vitamins
how are galaxies affected by the universe's expansion?
are passive participants in expansion - expansion of universe doesn't imply that individual galaxies/clusters are also expanding
where are asteroids most commonly found?
area between mars and jupiter
how can we identify a martian floodplain?
area contains diverse types of rocks as different substances flowed there
what are hot spots?
areas far from plate boundaries where heat nevertheless rises from earth's interior
what percentage of the total mass of the solar system do asteroids make up?
around .000002%
what percentage of the total mass of the solar system do comets make up?
around .0005-.03%
how old is io's surface?
around 1 million years old, since it has no impact craters
what is the minimum temperature of jupiter's stratosphere?
around 120k
how much mass is the sun converting into energy per second?
around 4 million tons
how many stars are in our galaxy alone?
around 400 billion
what percentage of stars are in binary systems?
around 60%
what is a continuous spectrum?
array of all wavelengths/colors of the rainbow
how is energy expressed during half-life decay?
as heat
what happens to the sun's magnetic fields during solar maximum?
as they strengthen, they flow from the sun's interior to its surface in the form of loops; those loops create regions of sunspot activity and help explain why leading and trailing sunspots in active regions have opposite polarities
what were people's views on meteorites prior to the 19th century?
assumed they had supernatural origins
where did earth get its water after its formation was complete?
asteroid bombardment
how can atoms leave behind fingerprints?
astronomers can map their vibrations and rotations by looking at radio and infrared waves
how is the inverse square law implied when looking at power spread across a sphere/planet?
at a given value, there's only 1 isotropic value of 1 since power spreads out evenly in all directions on a sphere; as spread increases, intensity decreases
what size must stars be to be able to consistently burn mass on their own?
at least .08 solar mass
how old are some of earth's oldest rocks?
at least 3.8 billion years old
what is the most likely scenario that explains how rna became dna?
atmospheric chemistry/seeds from space became amino acids; clay-catalyzed rna and pre-cells form, becoming self-replicating rna; natural selection caused by lots of mutations results in increased complexity/efficiency - cell becomes alive; rna becomes protected in cells; rna eventually mutates into dna
describe the angular resolution issue of direct detection
atmospheric turbulence blurs images, sometimes causing an entire solar system to blur together
what is an ionized atom?
atom whose electrons have enough energy to escape nucleus
what is an isotope?
atom with a neutron quantity higher or lower than its proton quantity
what is an ion?
atom with missing electrons or excess electrons
what is the majority of interstellar gas made of in the milky way?
atomic hydrogen - adds roughly 30% to total mass of gas between stars
what is the densest form of matter in the universe?
atomic nucleus
what does our study of amino acid formations allow us to conclude about life?
because life only uses left-handed amino acid molecules., life must have a common origin
describe the cores of jupiter and saturn
because of differentiation, both planets have cores made of heavier rock, metal, ice
why do mercury and the moon no longer have any geological activity?
because of their small sizes, their interiors long ago cooled too much to keep promoting convecction
describe dna replication in prokaryotic organisms
because they lack nuclei, transcription and translation occur simultaneously - so primary method to control type/quantity of protein expressed in a prokaryotic cell is through regulating dna's transcription into rna
how did galaxies form?
began as huge clouds of gas; as this interstellar gas cooled and contracted under gravity, it formed molecules and dust grains that absorb visible light
where do modern scientists believe that life on earth originated?
began in deep sea vents and hot springs where reactions catalyzed the development of life
what is the nebular hypothesis for solar system formation?
begin with a cold low pressure interstellar cloud rotating very slowly that, through the conservation of angular momentum, cloud begins to collapse into a rotating disc that spins faster as it collapses; the proto-sun contracts in the center and takes roughly 10 million years to evolve into the main sequence star
what happens to molecules with double carbon bonds?
bends are created in molecules as a hydrogen is thrown out; makes unsaturated fatty acids more likely to be liquid oils rather than solid fats at room temperature
what must the mass of a hydrogen fusing body be for it to be considered a brown dwarf?
between .013 and .08 solar mass
how many years ago did single-celled life dominate earth?
between 1.2 and 3.5 billion years ago
how much does earth's tilt vary?
between 22 and 25 degrees
what must ε be for a universe with complex chemistry to exist?
between roughly .006 and .008
describe the surfaces of europa and io
both are predominantly rocky due to heat of jupiter during their formations
where was most water found during earth's planetesimal accretion phase?
bound in oxidizing minerals such as iron oxide and silicon oxide
what do extreme changes in pH cause?
breakdown of structure of enzymes and cell membranes
what is nuclear fission?
breaking up of heavy atomic nuclei into lighter ones
what can all of the shortcomings of the big bang theory be answered with?
brief spectacular episode of inflation beginning 10^-36 seconds into universe's existance
what are nucleotides?
building blocks of dna and rna
how is the orbital eccentricity of an exoplanet measured?
by determining velocity curves using doppler method
how does the periodic table sort elements?
by number of protons and number of electrons in a neutral atom - aka by atomic number
what is the only direct method of measuring a star's mass?
by observing effect that gravity from another object has on a star
what is the equation that represents the relationship between wavelength and frequency?
c = λ*f where c = speed of light, λ = wavelength, f = frequency
how can we compute the amount of energy produced in the sun's nuclear reactions for energy production?
calculate difference of initial and final masses
what is the outermost galilean moon?
callisto
describe water's high specific heat
can absorb a great deal of kinetic energy before its temperature actually rises
describe the behavior of electromagnetic radiation
can behave as both a wave and particle despite these phenomena being seemingly opposite
what types of effects can changing the ends of molecules have on molecule's attributes?
can change from polar to nonpolar
how do cme's affect earth?
can disrupt spacecraft electronics; can push satellites into lower altitudes; can break satellites with their electrons; can distort gps signals; can expose astronauts and people on earth to excessive radiation
how can neutral hydrogen atoms acquire energy in space?
can rarely happen by colliding with other hydrogen atoms or electrons that happen to be nearby
on the smallest scales, how is total mass measured?
cannot be - total amount of mass is inherently uncertain and has fluctuations from one point to another; those ripples would be magnified by inflation and become huge structures today
why is life carbon based?
carbon atoms are part of most molecules found uniquely in living things
what are all of the possible shapes of hydrocarbons?
carbon chains, branched chains, rings
which spacecraft specialized in orbiting saturn?
cassini
describe the geysers on enceladus
cause dark "tiger stripes" on moon; plumes have chemical makeup similar to comets; there may be a subsurface ocean fueling the geysers
how do phospholipids contribute to cell membranes?
cells are surrounded by a membrane that contains a bilayer of phospholipids
what are the components of a spiral galaxy?
central bulge, halo, disk, spiral arms - all components rotate
what are proteins made of?
chains of amino acid monomers connected to form polypeptide chain of monomers that fold
what do changing electric currents produce?
changing magnetic fields
what are blackbody photons?
characteristics emitted by an opaque object - objects that absorb light then re-emit them; no photons/radiation is wasted
what happens in a magnetosphere?
charged particles spiral around in magnetic field, accelerating to high energies
who discovered the actual mechanisms for evolution?
charles darwin and alfred russell wallace - independently of each other
list some common causes of genetic mutations
chemical damage, uv radiation, random events/collisions between bases
what are hormones?
chemical signaling molecules
describe the structure of earth's moon
chemically and structurally similar to a terrestrial planet
what class star is our sun?
class g
what is the significance of jupiter's strong gravitational force?
cleans up most of the stray debris orbiting the sun - means it protects earth from major impacts
what is spica?
closest massive star - 260 light yrs away
what is the H II region?
cloud of ionized hydrogen; H II refers to a hydrogen that has lost its one electron; hot stars required to create this cloud are rare
how are geological eras of earth's history assembled?
collect strata worldwide
how are systems created?
combination of gravity and pressure
what are all organisms made up of?
combinations of elements
what state should all of the material in the universe originally been in before the big bang?
combined together in a simple/atomic dense hot state
what is halley's comet?
comet on such a large elliptical orbit that it only appears every 76 years - last seen in 1986
what is comet SL9?
comet that hit jupiter in 1994; caused string of violent impacts and is a reminder that planets today are still vulnerable to catastrophic impacts
what is the coma?
comet's atmosphere
what is the ion?
comet's tail
what are short-period comets?
comets that return in a time period measurable in human terms - a period less than a century
what could extraterrestrials do to contact us?
communication - use electromagnetic waves such as radio waves, which would be easy to hijack and form connections with
what is a ribosome?
complex macromolecule composed of structural and catalytic trna's and many distinct polypeptides
describe mars' seasonal polar caps
composed not of snow but of carbon dioxide
what are iron meteors?
composed of nearly pure metallic nickel-iron
how does an astronomer obtain a spectrum of a galaxy?
composite spectra of its many stars whose different motions produce red and blue doppler shifts
what happens to martian co2 during the winter season?
condenses into dry ice
if no energy is absorbed after being emitted from a central source at radius=0, what is the rate of total power received on a sphere?
constant
what is gravitational/hydrostatic equilibrium?
constant equilibrium between pressure and gravity within a star that keeps it from falling apart
describe the bonds of liquid water
constantly breaking then reforming
what's wrong with saturn's e ring?
constantly dissolves - scientists thing enceladus replenishes it since the moon has erupting geysers
describe the movement of atoms and molecules
constantly oscillating because their electric charges constantly move back and forth
what makes carbon nuclei unique?
contains a resonance that enhances the chance of beryllium grabbing an He nucleus to become carbon before beryllium decays
describe the absorption line spectrum of the solar atmosphere
contains same elements as earth but not in the same proportions
how does transcription initiation begin?
dna is unwound, forming a transcription bubble; enzymes and other proteins involved in transcription bind to the promoter at this time
what causes continental drift?
convection in the mantle pushes the earth's tectonic plates around
how is the sun fueled?
conversion of hydrogen into helium
what happens when a star has exhausted its carbon supply?
core collapses until the oxygen present fuses together into a new core
what's the only subtle change in the otherwise stable solar energy generation process?
core gets denser as it gradually becomes helium - temperature adjusts upward, so nuclear fusion runs faster, making sun 30% brighter than it originally was
what happens to the core of a red giant/white dwarf when their nuclear reactions stop?
core is supported only be degenerate electrons that gradually get closer together until some electrons squeeze into atomic nuclei and combine with protons to form neutrons and neutrinos - as those electrons disappear, core begins to shrink rapidly until some neutrons are squeezed out of nuclei and begin exerting a new force that can stop the collapse of cores that aren't too massive; however, even when core is saved, rest of star is still blown apart after the abrupt halt of the star's collapse creates a shockwave of energy produced by outflowing matter that triggers the explosion; the resulting explosion is called a supernova
what happens after all of a star's hydrogen has been converted into helium?
core pulls inwards, squeezing until helium is hot enough to react
where do the majority of uranus and neptune's masses come from?
cores
what are the 3 main sources of space weather?
coronal holes, solar flares, cme's
what are meteors?
cosmic dust that burns up in earth's atmosphere
what did the western enlightenment reveal about our place in the universe?
cosmos and humans are ruled by one set of universal laws equally applicable to all regardless of tribe; relentless questioning and self criticism of ideas is acceptable and necessary
what would happen to the periodic table if ε changed?
could become shorter or longer depending on what the change is
what type of chemical bond holds water together?
covalent
what are the two strongest chemical bonds?
covalent and ionic - both require significant energy to break
what are the three main types of chemical bonds?
covalent, ionic, hydrogen
how did bell labs contribute to big bang research?
created telescopes capable of detecting microwaves
what is the top layer of earth called?
crust
what are fault zones?
crustal plates sliding along each other
how does the lamarckian evolution begin?
culture experiences this after breakthrough of language
what are the origins of cosmic rays?
currently impossible to determine, but best theory is they came from supernovas; are a fairly recent phenomenon
which of the nitrogenous bases are one ringed pyrimidines?
cytosine and thymine
what are molecular clouds?
dark cloud of space dust accumulating in a singular location that blocks out uv starlight; denser than interstellar space on average
what happens when light with a continuous spectrum passes through a cool gas?
dark lines appear in the continuous spectrum since only photons having exactly the right energies can be absorbed by electrons as they jump up to higher energy orbits, thus imprinting a distinctive absorption light spectrum
where can molecules form in space?
dark regions protected from starlight
what are dark nebulas?
dense dust clouds
compare the density of interstellar clouds to the density of earth's atmosphere
density of interstellar clouds that are even larger than average still pale in comparison to the density of earth's atmosphere
describe the total mass of interstellar matter
density of interstellar matter is low but volume of space in which such matter is found is huge, so total mass is substantial
what does dna stand for?
deoxyribonucleic acid
what are the two types of nucleic acids?
deoxyribonucleic acid (dna) and ribonucleic acid (rna)
what is dna?
deoxyribonucleic acid - 2 strands of nucleotides linked together by hydrogen bonds
describe galileo's probe
deployed as an entry probe to study its outer atmospheric layers; probe data was sent to galileo then to earth; deployed on 12/20/1995 and operated for an hour before vaporizing
describe what the majority of mars looks like
desolate with numerous angular rocks interspersed with dune-like deposits of fine grained, reddish soil
what is the purpose of the doppler effect?
detect shifts between redshift and blueshift to indicate orbits
what is the purpose of absorption spectra?
detecting atoms between oneself and a star
what is the purpose of emission spectra?
detecting photon emission
what are some methods of searching for exoplanets?
detecting planetary transit, analyzing how a planet's motion affects its radial motion detected via the doppler effect as both objects orbit around their common center of mass
how can terrestrial planets be aged?
determining how long ago their surface solidified or counting impact craters or aging individual rocks
what is the deuterium bottleneck?
deuterium is fragile and broke easily during the big bang but is necessary to helium formation; without enough deuterium, early universe was filled with lots of hydrogen and only some helium - 75% hydrogen and 25% helium
what are tetrapods?
developed 380 million years ago; precursor to anthropods
where does charles darwin believe that life on earth originated?
developed in warm shallow seas and ponds
what is the earth's core?
diameter of 7000 km, outer part of it is definitely liquid iron/nickel but inner part could be solid
how are cells different if they all have the same dna?
different genes are expressed in each cell
how do our eyes perceive wavelengths of visible light?
different wavelengths look like different colors
why is finding exoplanets via direct imaging difficult?
difficult to determine whether the objects we're seeing are planets or brown dwarves
how is time-scale of the universe directly related to distance-scale?
direct relation as seen in hubble's law: 1/H=hubble time
how can cosmic rays be studied?
directly capturing them on earth or by observing reactions that occur when the rays collide with atoms in our atmosphere
how is the period of an exoplanet measured?
directly measured through doppler or transit methods
who was rosalind franklin?
discovered dna's structure
who was edmund halley?
discovered in 1705 that comets travel on very elongated ellipses and aren't necessarily traveling unpredictably
who was van leeuwenhoek?
discovers microscopic life in 1674; realizes that classification by biochemistry of cells can give much deeper insight into relationships among different species than classification by appearance alone
if there are other intelligent life forms in space, why might they have not tried communicating with us yet?
disinterest; they're already here; might not be paying enough attention to notice us; we could be quarantined
what do irregular galaxies often look like?
disorganized
describe the energy from new stars
disruptive and destructive
why is water called a "universal solvent"?
dissolves more substances than any other liquid since ionic compounds and polar molecules willingly dissolve in it thanks to its polarity
what is the force of attraction inversely proportional to?
distance between objects
what is the au unit?
distance from earth to sun - so the distance from earth to sun is 1 au
describe the presence of water on mars
doesn't have much - just a couple of frozen areas here and there, but there's evidence of it having liquid water when it was younger; however - mars still has permafrost right beneath its surface as indicated by blue regions on thermal maps
what are the properties of jupiter-sized exoplanets?
dominate radial velocity detections due to large mass but are actually rare; just because it has a high radii doesn't mean it has a high density; many orbit close to star, some in highly elliptical orbits; surface temperatures are high; radii have typically been larger than expected
describe the rotation of elliptical galaxies
don't rotate systematically and therefore rotational velocity can't be determined
describe the general structure of dna
double helix - two parallel strands of intertwining molecules with a backbone of alternating sugars and phosphates
what is the basic shape of dna?
double helix; two linked chains of 3e+9 nucleotides packaged into a chromosome
how do external events drive evolution?
dramatic environmental change drive change as seemingly insignificant traits could suddenly be determining an animal's survival or death
what are lunar marias?
dried up lava fields
what happens to material stripped from canyons during martian windstorms?
dumped in extensive dun fields at high latitudes
when were the six numbers essential to the universe established?
during brief inflation period
what are reflection nebula?
dust clouds close enough to luminous stars to be visible; typically looks bluer than the illuminating star
what is interstellar reddening?
dust clouds making stars look red
what is the most important way that dust gets redistributed by martian winds?
dust devils
what are cosmic rays?
dust particles that travel at high speeds; mainly atomic nuclei and electrons; abundant with light elements
what are the types of clouds that can form in mars' atmosphere?
dust, water-ice similar to earth, carbon dioxide
what are emission nebula?
dusty looking nebula with high uv emission
what is a black hole?
dying star in a state of ultimate collapse - its core did not survive
why could extreme life actually exceed the number of complex life forms currently on earth?
early earth had no oxygen and was ruled by anaerobic life
explain the two possible scenarios of eukaryotic cell development
early eukarya could've lacked a cell nucleus, but some larger eukarya may have developed membrane infoldings that allowed for specialized protein production, ultimately leading to the creation of a cell nucleus; mitochondria and chloroplasts might have evolved as small bacteria invaded a larger host cell, thus leading to a symbiotic relationship
what happened to earth last time a comet hit it?
earth grew in mass
what is the density of earth compared to the density of water?
earth is 5.5x denser than water
why is the center of the earth still hot?
earth was initially molten throughout and is still cooling
what is binding energy?
energy given up during the process of particles coming together under a strong nuclear force to become an atomic nucleus
what is atp?
energy molecule
what is power?
energy per second - typically expressed in watts
in the context of biology, what does the chemo prefix mean?
energy received from chemical reactions - not dependent on sunlight for energy
in the context of biology, what does the photo prefix mean?
energy received from sunlight
describe the theorized period of inflation following the big bang
energy released by universe's vacuum caused a sudden and dramatic expansion of the universe's size - perhaps by a factor of 10^100 times; all of the universe's particles had to have come from that vacuum in order for them to not have violated the conservation of mass/energy
what are the main functions of carbohydrates?
energy storage as starch/glycogen; structural support and protection as cellulose/chitin
list the properties of life
energy utilization - use of externally-obtained energy to create and maintain order within cells to grow and reproduce; response to environment - responds to existing and changing conditions, which is necessary but not sufficient on its own for life; growth and development - determined in part by heredity; reproduction - capability of making exact replications; evolutionary adaptation - not required but is ideal as it entails changes in structure allowing life to better adapt to environment
what is luminosity?
energy/time
what is total power per unit surface?
energy/time*meters^2
what is a helicase?
enzyme that unwinds and opens up the dna helix during replication
list common protein functions
enzymes, structural, transport, muscle contraction, cell motion, hormones, protective, storage, toxin defense, communication
compare earth's quantity of nitrogen in its atmosphere to venus'
equal
who was jean-baptiste biot?
established that meteorites came from space in 1803
when do high tides occur?
every 12.5 hours - so roughly twice a day everywhere on earth
what is the universal law of gravitation?
every mass attracts every other mass through a force called gravity
describe the breadth of the universe's expansion
everywhere and uniform - same expansion rate is everywhere; since the speed at which an object moves away from something else is proportional to its distance, the universe only looks like it's expanding away from only us; however, with V=Hd, we know that this appearance of expansion would be true no matter where you were
where did mitochondria come from?
evolved from a single species of bacteria that had invaded a cell - this theory is supported by the fact that the mitochondria has its own dna
compare the magnetospheric activities of the giant planets to giant exoplanets
exoplanets have milder magnetic activity
what do redshifts represent?
expansion of galaxies occurring universe-wide all at the same rate; definitive proof of this came from hubble telescope's key project on the cosmic distance scale
how does newton's third law affect planetary orbits around stars?
force of a star on a planet = force of a planet on a star, causing planet to orbit and star to wobble
what is the goal of quantum mechanics?
explain the duality of electromagnetic radiation being both a wave and particle
what is the plate tectonics theory?
explains how slow motions within the earth's mantle ove large segments of its crust
what are supernovae?
exploding stars responsible for the atoms that make up earth thanks to its intense heat
what was the miller-urey experiment?
exposed a model of the primitive atmosphere made up of NH3, CH4, H2O to electric sparks; produced amino acids and organic compounds - the types of amino acids used most frequently by organisms; demonstrates that building blocks of life could have been produced solely by earth's atmosphere; discovered that chemical reactions in deep-sea vents can yield the same products
describe a comet's tail
extension of comet's atmosphere; composed of dust and gas; always points away from sun
what usually triggers gravitational collapse?
external compression
what's the purpose of the mitochondria?
extract energy from food then produce ATP and CO2
what are the effects of uranus' tilt?
extreme seasons at the poles
what is a common convergent evolution?
eyesight - eyes have emerged from no less than 8 distinct lines because sight is so important
what are brown dwarves?
failed stars
what are lipids?
fats - biomolecules that don't readily dissolve in water; contain carbon, hydrogen, oxygen but has more hydrogen than oxygen relative to other carbohydrates; found in oils, cholsterol, hormones
where is carboxyl found?
fatty acids and amino acids
what are trans-fats?
fatty oils that have been artificially hydrogenated in order to become semi-solid - leads to less spoilage and increased shelf life
describe uranus when viewed as wavelengths
featureless
describe neptune's atmosphere
filled with convection currents and bright narrow methane clouds
what is pluto?
first distant icy world discovered beyond neptune
what do microfossils from africa tell us about the origins of life?
first evidence of life is from 2.7-3 billion years ago
describe the gradual move of microbial life from water to land
first moved into niches that protected them from uv and supplied water
how long does the sun's nuclear reactions for energy production take?
first step is difficult/takes awhile but other steps happen quickly
what are prokaryotes?
first/most primitive life forms; existed before the nucleus; make up single-celled organisms like bacteria and archaea
what are the two basic shapes of the biggest/most luminous galaxies?
flatter with spiral arms like the milky way and elliptical/blimp/cigar shaped
when did life move from ocean to land?
following cambrian explosion
interpret the meaning of V=HD
for every additional lightyear away a point is, expansion rates increases; galaxies are not really moving, though - space between them is just getting larger, so since there is more space between us and more distant galaxies, they appear to be receding faster (think of coins on a balloon)
what is λ in terms of one of the 6 numbers that control our universe?
force of antigravity controlling universe's expansion
what are nonpolar covalent bonds?
formed between elements that share electrons equally
what are polar covalent bonds?
formed between elements that share electrons unequally
how did the climate of mars likely change following its formation?
formed with higher surface temperature because of greenhouse effect but eventually got so cold that a runaway refridgerator effect occurred; however, conditions a few meters below the martian surface may still be warmer
what is the major purpose of hydrogen bonds?
forming water
where does our key evolutionary timing data come from?
fossil record
what type of rock plays a key role in aging different rock layers?
fossils
how was the magnetosphere discovered?
found by first us earth satellite - explorer 1 - in 1958
what are the terrestrial planets?
four planets closest to the sun - mercury, venus, earth, mars
what are the primary clouds of jupiter and saturn made of?
frozen ammonia crystals
how can our sun's lifetime be calculated?
fuel supply/burn rate = core mass/mass consumption
what is the formula for finding the speed of light?
fλ=c; frequency of waves*wavelength=speed of light
what is the formula for acceleration due to gravity when calculating it based on one's location near earth's center?
g=G(mass of earth)/(distance from center of earth)^2
what are barred spirals?
galaxies with bars of stars running through their centers; these bars are common, which likely means they're long-lived
what is an Sa galaxy?
galaxy with large and luminous central bulb, faint and tightly coiled arms, inconspicuous bright emission nebulae and supergiant stars
what is an Sc galaxy?
galaxy with small central bulb, loosely wound arms, prominent emission nebulae and supergiant stars
which spacecraft specialized in orbiting jupiter?
galileo
list the most common waves of the electromagnetic spectrum in order from shortest to longest
gamma rays, x-rays, uv rays, visible light, infrared/heat radiation, microwaves, radio waves
what is the largest galilean moon?
ganymede
what happened to the universe about 380,000 years after the big bang?
gas cooled; when cooled to same temperature as a star's surface, neutral hydrogen atoms could finally survive; universe became transparent and opaque, allowing light/microwaves to travel; particle recombination began as free electrons quit interfering with photon travel; first atoms began to appear
describe the range of gravity and electromagnetic forces
have infinite range with strength dropping as a square of separation - inverse square law
where did early theories of evolution come from?
geologists who believed that earth's old age allowed for more time for gradual change in species
what happens to the surface of mars during the winter/
gets surface frost in form of dry ice
what is the most common lipid?
glycerides
what are fat molecules made of?
glycerol and fatty acids; fatty acid attaches to each of the three oxygen atoms in -OH groups of glycerol molecule
describe the direction of upper winds blowing from the equator
go northward since warmed air rises then veer rightward as they move closer to earth's axis at the north pole
like all energized particles, what is the natural energy tendency of electrons?
go to lowest energy level
what are quiescent prominences?
graceful loops of plasma/ionized gas that remain stable for hours/days
why does mars have few gullies?
gradual dust buildup conceals them all
how does space dust form?
grains condense in regions where gas is dense and cool
what holds planets, stars, and galaxies together?
gravitational force
describe the makeup of chloroplasts
have inner and outer membranes that make them strong
how would planets be affected by binary orbits?
gravitational perturbations will result in rapid obliquity changes, unstable climate, uncertain life conditions
how did structure form in the universe?
gravitational pull of dense fluctuations in the fabric of the universe
what keeps our planets in their orbits?
gravitational pull of sun
what is tidal heating?
gravitational stress deforming and flexing planets' structures; stress is caused by unequal gravitational pulls on 2 sides of a body
what are the forces that act on matter?
gravity and electromagnetic force
describe the relationship between gravity and pressure acting on a star
gravity wants to collapse a star while pressure holds it up
what must the mass of a hydrogen fusing body be for it to be considered a star?
greater than .08 solar mass
why could temperature estimates of exoplanets wind up being lower than actual temperatures?
greenhouse effect
what is the goal of all small nuclei?
grow and be as stable as iron
what is the units of the angular momentum of an electron's orbit?
h/2(pi) where h=planck's constant
what does earth's ozone allow?
habitability of o2 breathing animals
what was the universe like 3 minutes after the big bang?
had already cooled down to 10 million degrees; after that, was too cold for any more fusion reactions to occur; no nuclei heavier than helium could form
why does venus not have co2-rich rocks?
had no oceans for them to form in
how big is mars compared to earth?
half of its size and 1/10 its mass
how much fuel has our sun used so far?
half of its total
how much energy does saturn emit compared to jupiter?
half of jupiter
how did the first evidence of light absorption happen?
happened on accident while scientists were trying to study a star's light in 1904
how is earth's lithosphere divided?
has 16 different plates that float on top of convection currents that cause continental drift
why is mercury hard to view from earth?
has a highly elongated orbit
why does jupiter have deserts?
has areas of downdrifting cool, dry gas
why does io have a young geological surface?
has greatest number of active volcanoes in the solar system because of jupiter's tidal forces
what is comet encke?
has shortest known period of 3.3 years
why is venus considered earth's twin?
has similar size, mass, density, and interior composition of an iron core, mantel, crust
describe enceladus' surface
has water geyser's indicative of a global subsurface ocean
describe the surface of callisto
has yet to fully differentiate; covered with impact craters and ice spires
why are hotter objects white or blue in color?
have a smaller maximum wavelength
what is the only likely prediction we have of what aliens will look like?
have at least two eyes and dexterous limbs
why is the study of seasons on the giant planets almost impossible?
have such long orbits
what are nonpolar molecules?
have symmetric charges - even distribution of charges throughout molecule
how does newton's theories help explain orbit?
he states that an object in motion is in continuous motion; therefore, an object in orbit is in a continuous fall due to an increasing sideways velocity; in other words, an object is trying to fall to earth but earth keeps curving away from it
describe the structure of glycerides
head is a glycerol - an alcohol; 2nd part is a fatty acid followed by a long chain of hydrogen and carbon atoms that terminates with a carboxyl functional group; this termination makes it an acid
what types of atoms are least abundant in older stars?
heavier atoms
describe the mass of most exoplanets
heavier than earth
what are some of the most stable/unreactive atoms?
helium, neon, argon
list some personality traits unique to humans
heroic sacrifice, loyalty to tribe/leader, unquestioning acceptance, ability to manipulate and control less intelligent animals
describe the clouds around saturn's north pole
hexagon-shaped - scientists don't know why
what was the early universe made of?
high energy hot electrons, neutrons, protons that made fragile molecules and atoms incapable of existing
what is the relationship between wave height and energy?
higher energy waves have higher energies and vice versa
how does temperature affect power?
higher temperatures result in a shorter wavelength at which max power is emitted and vice versa
what is olympus mons?
highest point on mars - a volcano that's less than 100 million years old; may be the largest volcano in the solar system
what's older - lunar highlands or lunar marias?
highlands
what are lunar highlands?
highly cratered regions from a period of heavy bombardment
describe the orbits of hot jupiters
highly eccentric
give an example of how religion is affected by meteorites
holy black stone in mecca is likely a meteorite
what is a wavelength?
horizontal length covered by one wave cycle
what type of exoplanet is the easiest to find?
hot jupiters
what is at the center of the earth?
hot metallic iron/nickel core
what are the volcanoes of io primarily composed of?
hot silicate lava like volcanoes on earth
what is kirchoff's 1st law of thermodynamics?
hot, low density gas emits light of only certain wavelengths; atomic collisions in the gas excite electrons to higher energy orbit, but after less than 1 millionth of a second, electrons tend to drop down to lower energies and emit a distinct emission light spectrum - a photon
what is kirchoff's 2nd law of thermodynamics
hot, opaque glowing objects that are either solids or gasses emit a continuous rainbow spectrum because its emission lines have been smeared into a continuous blend
what is wien's law?
hotter blackbodies emit higher frequency photons since electron collisions between particles are more energetic
describe venus' temperature
hottest planet in the solar system with volcanic plains covering 80% of its surface
what's the significance of the kepler-62 system?
houses at least 2 habitable planets
how is intelligence determined?
how capabilities are utilized
what is the most active field of astronomical research?
how galaxies evolve over a universe's lifetime and are affected by collisions
why is eq a crude measure of intelligence?
how neurons are connected in brain also plays a role in intelligence
what is H in V=HD?
hubble's constant - 15 miles/second/million light years; a slope
what is V=HD?
hubble's law - redshift recession velocity is directly proportional to the distance of each galaxy
how did humans taking control of animals advance our evolution?
hunting/gathering ceased
what are the most important biological molecules for sustaining life?
hydrocarbons/carbohydrates, proteins, lipids, nucleic acids
what chemical dominates all of the jovian planets?
hydrogen
what are the sun and most stars mainly made up of?
hydrogen and helium
what majority of two elements most likely came from the big bang?
hydrogen and helium
what are reduced compositions?
hydrogen dominated compositions
what is deuterium?
hydrogen with a proton and neutron; necessary in the formation of nuclei with an atomic mass greater than two
what are the most reactive atoms?
hydrogen, carbon, sodium
what are the most important components of interstellar dust?
hydrogen, helium, oxygen, carbon, nitrogen, magnesium, silicon, iron
what do more complex molecules usually consist of?
hydrogen, oxygen, carbon, nitrogen, sulfur
what are ring and moon systems mainly made of?
ice and dark matter
what are comets?
icy counterparts to asteroids formed beyond galaxies' frostlines
what is neoteny?
idea that humans are born extremely prematurely and require roughly 20% of their lifetime to fully mature - only our heads are fully developed by the time we're born
what is the sunspot cycle?
idea that number of sunspots varies systematically in cycles about a decade long
what is the planetary selection effect?
idea that planets like hot jupiters are inherently easier to find and will thus be the most commonly found exoplanets
what is refundancy?
idea that same amino acids can have different triplet base codes
once we're able to successfully identify habitable earths, what will humans then begin to try doing?
identifying and contacting intelligent life
what is the doppler effect?
if a light source is approaching or receding from the observer, light waves will be crowded more closely together or more spread out, respectively - applies to sound and light waves; this is the concept behind redshifting and blueshifting
what's the only way we'll see a planetary transit?
if earth lies in plane of planet's orbit
how is the majority of earth's composition and structure studied?
indirectly - mainly through seismic wave study since these waves travel through the entirety of the planet like a struck bell
describe the relationship between earth's magnetic axes and rotational axes
imperfect allignment
how did jupiter contribute to water appearing on earth?
in early age of solar system, jupiter pulled comets towards earth during hadean age
where did life on earth originate?
in oceans
what is the purpose of neutrons?
in our universe, two protons repel each other so strongly that the strong interaction force can't hold them together without the aid of neutrons
describe the cultural evolution of humans
individual, tribe of hundreds, society of millions as cultures, experiences, and knowledge was shared more often
how large is our universe?
infinite in terms of time and space but finite in terms of light-producing matter
what is the optical wavelength range when using direct detection?
infrared
what colors can penetrate dust clouds more easily?
infrared - not ultraviolet
why are meteorites so appealing to be studied in labs?
include oldest and most primitive material available for direct study - their average age is 4.56 billion years
what is dna mismatch repair?
incorrectly added base is detected and replaced after replication
list the stages of dna replication in order
initiation, elongation, termination
what are the three phases of protein synthesis in order?
initiation, elongation, termination
what is the umbra of a sunspot?
inner darker core
describe jupiter's core
inner density is so great that hydrogen becomes solid and metallic
what is a spectrometer?
instrument used to cause dispersion and create a spectrum
what's the problem with trans-fats?
intaking them can lead to increase in LDLs - bad cholesterol
what specific type of extraterrestrial intelligence are we looking for?
intelligence that we can communicate with
what is the inverse square law?
intensity of an effect changes in inverse proportion to the square of the distance from the source
what are chemical bonds?
interactions between 2+ elements resulting in molecule formation; occurs when atoms share electrons in their outermost shells
what does E=mc^2 represent?
interchangeability of mass and energy
what evolutions took place as prokaryotes became eukaryotes?
internal cell compartmentalized certain specialized functions and eventually developed a nucleus and protein production machinery; cell absorbed bacteria and established a symbiotic relationship with the ensuing organelles that formed
what are some possible ways that humans could contact intelligent life?
interstellar space trips of thousands of years - one-way voyages of colonization that will require giant space stations traveling independent of a star's gravitational pull; alternatively, machines could be sent though they would have a higher likelihood of failure
what is the valles marineris?
largest canyon system in the solar system; found on mars; 3000 km wide and 8 km deep; caused by tectonic cracks
what is the maunder minimum?
interval of significantly low sunspot events; lowers auroral activity; could have contributed to unseasonably low temperatures in northern hemisphere, but no data can yet prove this
what are radio waves?
invisible electromagnetic waves
which galilean moon is closest to jupiter?
io
what are the innermost galilean moons?
io and europa
what are the rockiest moons of jupiter?
io and europa
list jupiter's moons
io, europa, ganymede, callisto
list jupiter's moons in order from most to least dense
io, europa, ganymede, callisto
what does the uv radiation from stars do to nearby hydrogen?
ionizes it, leading to spectacular astronomical photos; ionization quickly ends but immediately begins again due to continuous heat
what evidence supports the theory that an asteroid killed the dinosaurs?
iridium-rich sediment layer along with a now-submerged impact crater on the mexican coast shows that a large impact occurred there at the same time that the dinosaurs died
how are galaxies enriched with heavier elements?
iron absorptions from neutrons ejected by supernovae
why is mars so distinctively red?
iron oxides in its soil
what are the three broad meteor classes?
irons, stones, stony-irons
why is jupiter a failed star?
is about 80x too small
describe electromagnetic radiation in terms of photons
is both a wave and stream of photons
why is the existence of a terrestrial planet like ours so rare?
is difficult to get water on it - we were lucky enough to have a jupiter capable of delivering water via asteroids
what happens to martian co2 during the summer season?
is hot enough to sublimate from dry ice to gas
how can ice float and insulate?
is less dense than liquid water - this is a significant contribution to maintaining life on earth
what is the significance of earth's average density?
is much higher than that of the average density of surface rocks, which is only around 3x denser than water - indicates the presence of something denser
what makes earth so unique compared to the other planets in the solar system?
is only planet currently in sun's habitable zone; saturn and jupiter's gravity protects earth from potentially deadly asteroid impacts; has a large moon thanks to a chance collision during the formation of the early solar system; is terrestrial; good ocean-continent balance; has plate tectonics; has a magnetic field
why does mercury not have an atmosphere?
is too close to sun
why does the moon not have an atmosphere?
is too small
what is heavy hydrogen?
isotope of hydrogen with an atomic number of 1 but atomic mass of 2; aka deuterium
how can we see the spectrum of a gas that doesn't emit a continuous spectrum?
it can be heated up until it's hot enough to glow with its own specific light spectrum
how could europa force us to expand our definition of a habitable planet?
it could house life, which means that life not in closer proximity to its sun is possible
why has the lunar surface barely changed in the past billions of years?
it experiences little to no weather
why does carbon have such a strong presence on earth?
it has 4 outer shell electrons and would therefore like 4 more for stability - so it has 4 linkages, making it optimal for forming complex molecules with strong covalent bonds
why does water have a high specific heat?
it needs a high energy capacity in order for it to continually make and break hydrogen bonds
what is the earth's mantle?
largest part of solid earth - stretches from base of crust down to depth of 2900 km
why does the presence of intelligent life elsewhere not mean that the life is immediately detectable?
it's difficult to assess presence of intelligent life on another star system without sending out intrusive probes unless the intelligent life was technologically advanced like us
why could our technology be behind that of any other extraterrestrial intelligence?
it's statistically likely that we're a younger species
what's important about analyzing earth's unique attributes?
it's unusual yet produced the perfect place for life - we need to figure out exactly why
why do we know that the sun's atmosphere is over a million degrees?
its atmosphere can highly ionize iron as a result
why is jupiter's coloring so baffling to scientists?
its hydrogen atmosphere should make it almost colorless
what can the doppler method tell us about a planet?
its mass
what does jupiter's low mean density indicate?
its planet is largely liquid
what part of mars can most easily be seen from a telescope?
its polar ice caps
why is polar a great solvent?
its polar structure makes it capable of dissolving ions of other molecules (called solutes)
why does the earth have seasons?
its spin axis isn't exactly perpendicular to its orbit around the sun, therefore all land masses are closer and further away from the sun at different times
why is venus so hot?
its thick co2 atmosphere locks heat in - strong greenhouse effect
what is nuclear fusion?
joining together of atomic nuclei
where is most of the planets' total material concentrated in?
jupiter
which giant planet has no seasons?
jupiter
which planets have a chemical makeup similar to the sun?
jupiter and mars
what are the gas giants of our solar system?
jupiter and saturn
what are the giant/jovian planets?
jupiter, saturn, uranus, neptune
what are the jovian planets?
jupiter, saturn, uranus, neptune
what is the most massive planet in the solar system and its size?
jupiter; 18991e+23 kg
how long is a martian day?
just over 24 hours
what is the size of typical interstellar dust grains?
just smaller than a wavelength of visible light - if grains were any larger, starlight would be blocked instead of reddened
how does the moon affect earth's seasons?
keeps them from getting out of control
what's the largest exoplanet system that's been found so far?
kepler-62 - planets are large and closely spaced together
who were luis and walter alvarez?
known for discovered a worldwide thin layer of iridium laid 65 million years ago that contained no dinosaur fossils and thus indicates some large comet/asteroid impact
why do astronomers think europa is the youngest galilean moon?
lacks craters
describe cassini's probe
lander
what is philae?
lander of the rosetta mission; landed on jupiter-class comet 67p; bounced on landing into a shadow, which caused its solar-powered battery to shut down after only a few hours of operation
what is the ultimate tool of social cooperation?
language - extremely complicated/expressive speech that was an accidental development
describe jupiter's magnetic field
large - similar to sun's
describe the continental shelves of continents
large and shallow
what are sunspots?
large dark features on sun's surface caused by increased magnetic activity that look darker because their cooler
what are biological macromolecules?
large molecules necessary for life
what type of moon is most ideal for planets to sustain life?
large moon - is rare but most ideal
what types of exoplanets did kepler have the easiest time finding?
large short period exoplanets
what are primitive rocks?
largely escaped heat-induced chemical modification so can tell us much about early history of planetary system
what size do particles have to be to create major fireballs in the earth's atmosphere?
larger than golf balls
what are martian outflow channels?
larger than runoff channels - large enough to have been flood channels; regions where these channels originated contained abundant permafrost until some local heating source released he water as catastrophic floods
what is the trappist-1 system?
largest batch of earth-size habitable zone planets to be detected around a single star; 3 of the planets are firmly in habitable zone and has 7 planets total
what was the viking spacecraft?
launched in the 1970s - two orbiters surveying mars and relaying communications for two landers on the surface
what do gene sequences determine?
lead to different amino acids being added to polypeptide chains, thus causing change in protein structure and function
describe the current solar cycle
least active in recent history
what are some ways to "win natural selection"/have higher fitness?
leave behind many descendants regardless of how many could die or invest lots in a few descendants so that they'll succeed; protect territory so that food sources won't be exhausted; closely related species are altruistic to each other; dominate sexual rivals through high visual attraction
how does unequal reproductive success contribute to natural selection?
leaves larger progeny number that possess successful traits that are subsequently transmitted to an increasing fraction of the population through natural selection
what does the interval between successive transits of a planet indicate?
length of year/orbital period for that planet
what was the oxygen concentration on earth 2.35 billion years ago?
less than .002% of current oxygen levels
what is the size of the typical meteor?
less than 1 gram
compare mars' atmospheric surface pressure to earth's
less than 1% of earth's
how close does a supernova need to be to an organism to kill it?
less than 50 light yrs
what is infrared light?
light beyond the color red
what is ultraviolet light?
light beyond the color violet
how does the inverse square law apply to light?
light gets weaker as it gets farther from its source
what is triglyceride?
lipid made of a glycerol and three fatty acids - a dietary lipid
what are titan's lakes likely made out of?
liquid ethane and methane - its temperatures are too low to have water lakes
why is finding life more complicated than the drake equation may imply?
liquid water requires special conditions to survive that go beyond the drake equation
what are endoliths?
live a few km below surface in the water trapped in rock pores
how does overproduction and competition for survival contribute to natural selection?
local population reproduces at a rate that cannot be sustained by all of the resources in the environment, so some of the organisms must struggle to survive
what do volcanoes on earth indicate?
locations where magma has risen to surface
what are polysaccharides?
long chain of monosaccharides linked by covalent bonds
describe mars' climate cycles
long-term due to changing orbit and tilt
what is the main job of fats?
long-term energy storage
what does starlight reddening indicate?
long-wavelength radiation transmits more efficiently than short-wavelength radiation
how can we roughly guess the temperature of a star?
look at color of light dominating its appearance
how can we estimate the temperature of a planet's atmosphere?
look at its brightness
what's a novel method of hunting for life on mars that scientists are beginning to utilize?
look for fossils
how do astronomers analyze the movements of distant stars?
look for physical changes in star's position in sky and analyze star's doppler effect
how is a solar atmosphere's composition determined?
looking at its absorption line spectrum
what is denaturation?
loss of function of a protein
what must all habitable planets have?
lots of liquid water since all life on earth started in water and all known life forms need water to survive
what is the troposphere?
lowest layer of earth's atmosphere
what is required for us to find fossils of primitive animals without bones?
lucky preservation conditions
what did brent tully and richard fisher discover?
luminosity of a spiral galaxy is related to rotational velocity - so a spiral galaxy's luminosity could be estimated by measuring its mass, which can be estimated through rotational velocity
what are sedimentary rocks?
made of fragments of igneous rocks or shells of living organisms
describe the surface of europa
made of ice rafts moving on a liquid surface - indicates presence of ice tectonics; there could be a miles-deep global ocean under the ice made of salt since the moon's electric field is similar to how salt conducts electricity
describe the nucleus of a comet
made up of frozen ice and rock as well as dark, primitive hydrocarbons and silicates similar to material thought to be present on dark, primitive asteroids
what type of fields do moving electric charges produce?
magnetic fields
describe saturn's rings
mainly icy particles spread out into several vast flat rings
describe the jovian planets
mainly made of hydrogen and helium, all rotate rapidly, could all be considered failed stars
what are the nuclei of most comets like?
mainly made of ice
describe the tails of comets
majority have none and remain perpetually frozen unless they enter a solar system - this is when they grow tails
what are the interiors of jupiter and saturn likely made up of?
majority hydrogen and helium
describe the nucleus of a comet
majority of it is frozen - like a dirty snowball
what are eukaryotes?
make up evolvced life forms; havec complex and diverse cell structure
what are phospholipids?
make up majority of plasma membrane; have both hydrophobic and hydrophilic regions - fatty acid region faces away from water and hydrophilic group faces water
what is the purpose of eukaryotic mrna maturation?
makes molecule more stable than prokaryotic mrna
describe the red giant phase in a star
makes up a small percentage of a star's lifetime; ends temporarily when core temperature reaches 100 million degrees celsius, when a new nuclear fusion reaction powers core through a triple alpha reaction
what is chitin?
makes up large portion of outer skin/cuticle of arthropods
what are the most common types of planets in the galaxy with orbital periods of less than 2 years?
mini neptunes and super earths
how could super-earths sustain life?
many super-earths could have deep underground oceans heated by their large cores that could provide a home for life
other than venus and the moon, what is the brightest object in the night sky?
mars
what does evidence of ancient martian rivers and lakes suggest?
mars was once warmer with a thicker atmosphere
what is the formula for momentum?
mass * velocity
what is the formula for angular momentum?
mass * velocity * radius; as r decreases, v increases (think about an ice skater pulling in her arms while spinning)
why is mass the most important property of a star?
mass determines luminosity, size, and surface temperature
what does the formula E=mc² mean?
mass is related to energy via speed of light
what is not included in a galaxy's total calculated mass?
mass of material beyond a visible edge
how does the mass of all the matter in the galaxy compare to the mass of the sun?
mass of matter is 10 billion times greater than sun's mass
what type of planets are we most likely to find with the doppler technique?
massive planets orbiting close to their star
what are hot jupiters?
massive planets orbiting very close to their stars
what happens when covalent bonds are broken?
massive release of energy
what do the stars of galaxies with ongoing star formation look like?
massive stars
describe the shells of massive stars
massive stars with iron cores have shells of decreasing temperature in which nuclear reactions involve nuclei of progressively lower mass; decreases because there's a limit to how long process of building up elements by fusion is
what are nutrients?
matter an organism needs to survive; many nutrients come in form of biological macromolecules
what is einstein's theory of relativity?
matter can be considered a form of energy that can be converted into energy; in other words, we can convert energy into mass and mass into energy using the conversion factor c^2
why is ice less dense than water?
maximum number of hydrogen bonds form, forcing molecules to spread far in order to bond
what is pH?
measure of hydrogen ion concentration, which determines a solutions acidity/alkalinity
what is temperature?
measure of motion/kinetic energy of molecules
describe hubble's work with cepheids
measured them to improve the accuracy of extragalactic distance
what is half-life?
measurement of rate at which atoms decay
how are individual rocks aged?
measuring radioactive decay - half life
where do scientists believe that earth's water could have come from?
melted ice of space dust; asteroids and comets
what temperature must rocky planets be heated to in order to differentiate?
melting point of rocks - over 1300 k
what are the only planets in the solar system without moons?
mercury and venus
what is the least massive planet in the solar system and its size?
mercury; 3.3e+23 kg
what is mrna?
messenger rna - translated to become a protein
why are comets not the same thing as meteors?
meteors burn up in the atmosphere whereas most comets have set orbits
what was earth's original atmosphere composed of?
methane and ammonia
what types of organisms likely survived the "snowball earth" period?
microbes living in sub-surface arctic rocks within pockets of water that melt roughly 20 ays per year
what are microbes?
microscopic organisms - dominant form of life on earth in terms of mass and volume; vary remarkably in size, cell structure, biochemistry, genetics; most are harmless to humans and many are crucial to our survival
what conditions on earth are favorable to life?
mild temperatures thanks to protective atmosphere - aka greenhouse effect, presence of liquid water in large quantities, magnetic field to protect us from solar radiation, location of earth in relation to sun, tectonic plate activity
what is human society?
mind boggling coordination of individual actions; we're dependent on trust - need other humans to do things for us; also utilize voluntarily cooperation - making humans do things for you because it'll be worth your while
what are stony-iron meteors?
mixture of stone and metallic iron
why do chemical recations occur best in liquid mediums?
molecules are more readily transported
what are amino acids?
monomers that make up proteins; are made up of a central carbon bonded to an amino group, carboxyl group, and hydrogen atom
where do the majority of earth's meteorites come from?
moon and mars
what's mars' orbit like compared to earth's?
more elliptical - causes long, cold winters in southern hemisphere
what does a greater planetary tilt indicate for those on earth?
more extreme seasons
what will happen to the surface of meteorites that successfully reach the surface of earth?
more likely to acquire a frost coating than set ground on fire
how common are proteins?
most abundant organic molecules in living systems
what are surge prominences?
most active, move as fast as 1300 km/s
what's the significance of the voyager missions?
most distant spacecraft launched by humanity; performed a grand tour - gravity-assisted flybys by all 4 gas giants
what do the oldest regions of planets look like?
most heavily cratered terrain since more time has elapsed since something swept region clean
what type of orbit should life-sustaining planets ideally have?
mostly circular to allow for seasonal variations without too strong of an axis tilt
what is radial velocity?
motion going towards or away from an observer
what is radial velocity?
motion of an object as it moves towards or away from us
where do earths' circulating electric currents come from?
motion of magnetic material moving in earth's liquid core
what are the three basic properties of a planetary system that any theory of its formation must explain?
motion, constraints, chemical constraints, age constraints
what produces the currents that make up earth's magnetic fields?
motions in our molten iron core - changes in earth's polarity is dependent on these random motions
how much gas and dust do irregular galaxies have?
much gas, variable dust amounts
what type of population must a species be like in order for natural selection to occur?
must have genetic variation
what was the lunar prospector?
nasa explorer from 1999 that crashed into the surface of the moon near the south pole's craters but found no water
where are earthen volcanoes most common?
near plate boundaries and hot spots
how must a planet's surface be habitable?
needs to be large enough to retain internal heat for billions of years in order to drive motions of a living world
what is the charge of an electron?
negative
which giant planet is the densest?
neptune
describe the energy of neptune and uranus
neptune has small internal energy amounts while uranus emits no measurable amount of internal heat
what is most interstellar medium filled with?
neutral/nonionized hydrogen that can't emit or absorb light
what is the majority of the energy from a dying star?
neutrinos - combination of electrons and protons that form a neutron and a high energy neutrino
describe venus' crust
never broke up into multiple plates - has a thicker and stronger lithosphere than earth likely because of its high surface temperature - any water in its crust/mantle is baked out over time
when was pluto first visited?
new horizons in 2015
what does earth's mid-atlantic ridge tell us about the planet's magnetic fields?
new magnetic rock is steadily forming on its floor; that new magnetic crust preserves the magnetic field present at the time it solidified, which means that field reversals occur about every 500,000 years - the period of time it takes to create a new magnetic crust at rift zones
what are the key building blocks of chemicals in all living things?
nitrogen, oxygen, carbon, hydrogen, sulfur, phosphorus
what are the three components of nucleotides?
nitrogenous base, pentose sugar, phosphate group
does neptune have any rings?
no
has evidence of life on mars been found?
no - no traces of organic molecules found
can io sustain water?
no - too hot
what is the charge of a neutron?
no charge
describe the orbital angular momentum of electrons when they're at their lowest energy level
no momentum; despite this, electrons still orbit because of the uncertainty principle
how old are young stars?
no more than 1 million years
what happens after a star's core becomes iron?
no nuclear reaction can extract energy from iron, making iron the most stable element; fusing iron consumes energy and fissioning iron consumes energy - continuing to crush the core until it collapses due to pressure because the continuous fusing and fissioning removes the heat holding up the core against gravity; pressure vanishes and core implodes at speed of light as core density becomes so high that electrons can no longer exist - instead, the electrons just bury themselves back into protons
how would the decay of radioactive elements in a rock alter a rock's appearance?
no visible change would be detected as radioactive atoms are simply replaced with decay products
how many 10 km-sized objects currently cross earth's orbit?
none
why has no shower meteor ever been recovered for laboratory analysis?
none have survived flight through atmosphere because they break up so easily
describe the elements that make up terrestrial planets
not commonly found in universe
describe vaporization on comets
not constant - occurs randomly
how many cepheids are near earth?
not many - even though they're fairly luminous, cepheids can only be detected in around 30 near galaxies using ground-based telescopes
what is the overall data that all the mars rovers recovered?
not much organic compounds/molecules found; no microorganisms found
how is doppler shift detected?
not through just a continuous spectrum but through wavelengths of absorption lines on a spectrum
describe the polarities of typical sunspots observed in pairs
one usually has polarity of a magnetic pole seeking north while other has opposite polarity; during a new sunspot cycle, that polarity reverses
what is a common method for characterizing galaxies?
noting ratio of mass in unit of suns to light output
where does the sun's energy come from?
nuclear fusion in its core
if a monomer is a nucleotide, what is the polymer?
nucleic acid such as dna, rna
what is dna made of?
nucleotide + nitrogenous base + sugar/deoxyribose
what does the drake equation tell us?
number of technologically advanced civilizations currently in the milky way
what is frequency?
number of wave cycles per second
how many mitochondria are in one cell?
numbers from few to a thousand
what is ozone?
o3 - heavy oxygen with 3 atoms per molecule instead of 2
what are super earths/hot neptunes?
object that's at least 2x earth's size
what is redshift?
objects moving away; galaxy spectra lines are displaced towards longer wavelengths as light waves move away - towards red on the visible spectrum
what is blueshift?
objects moving towards; as light waves approach, wavelengths appear shorter - near the blue spectrum
how did charles darwin come up with his theory of evolution?
observed how beak shape in galapagos finches could have changed over time - the sizes varied each generation as a part of natural selection due to the availability of certain kinds of seed sizes/densities so that the bills were larger as seeds were more plentiful and smaller when seeds were rarer
how is the rotation speed in spiral galaxies measured?
obtaining spectra of stars/gas and looking for wavelength shifts in the spectra produced by the doppler effect
what causes variations of monosaccharides to occur?
occurs as atoms are arranged differently in carbon chains
how can an unstable orbit be obtained in a binary star system?
occurs when stars and planets are spaced too far apart from each other to establish a center of gravity
what types of bodies of water would planets with life ideally have?
oceans
what are the special conditions necessary for the development of complex life?
oceans, atmosphere, continents, ocean-continent balance, climate stability, large moon
what is mars' largest mountain called?
olympus mons
what is vesta?
one of the largest asteroids in our solar system - so large that it appears to be differentiated
what is alpha centauri a?
one of the nearest stars other than the sun
describe a molecule with a polar bond
one side of a molecule has a slightly positive charge while other side is slightly negative
how thin are saturn's rings?
only about 20m
how much does the energy output of the sun vary during solar cycle changes?
only around .1%
what's the significance of the kt impact?
opened way for mammals then humans to rule the earth after wiping out large herbivores and carnivores, leaving behind only small insect-eating mammals that later evolve into humans
what is an electromagnetic force?
operates on charged particles; holds atoms and molecules together; can be attractive or repulsive
why do solar flares happen?
opposite-pointing magnetic fields release energy by interacting with and subsequently destroying each other
what are the main causes of natural selection?
overproduction and competition for survival, individual variations, unequal reproductive success
what made earth ideal for containing life right from the start?
orbits the right star with a main sequence lifetime that must be long enough to allow evolution for billions of years - should also be bright enough that habitable zone occurs at a sufficient distance to avoid tidal locking; parents of planets with complex life are probably limited to within a factor of 2 of the sun's mass
what type of molecules are hydrocarbons?
organic molecules
what is a heterotroph?
organism that acquires its carbon
what is an autotroph?
organism that makes its own carbon
what is a template strand?
original dna strand in the transcription process
how did humans diverge from gorillas and chimps?
our quantity of neuronal connections was increasing at a faster rate
how was our solar system formed?
our star, surrounded by a dusty disc of gas, condensed itself and the gas into planets; the carbon, oxygen, and iron left in our solar system represent the remains of that disc
where do comets come from?
outer solar system
what causes the most significant affects to chemistry?
outermost electrons of atoms
what does the .71% efficiency of the sun's energy generation process signify?
percentage of initial mass lost during proton-proton chain so that the total mass of inputs is .71% greater than the total mass of outputs
why is earth's ocean perfect?
perfect ocean-continent balance with 70% water and has enough weathering for the ocean to not be too acidic
how can sun tap energy in nuclei?
perform nuclear fission
what does the brain allocate the majority of its energy to doing?
performing hand and mouth movements
when did the dinosaurs rule the earth?
period of 225-65 million years ago
what is a sunspot maximum?
period of a large number of visible sunspots
what is a sunsport minimum?
period of a small number of visible sunspots
what was the snowball earth period?
period of global glacier coverage that was more extreme than the ice age
list the main planetary properties
period, distance, eccentricity, inclination, mass, size, density, atmospheric composition/temperature
how are electric fields related to magnet fields?
perpendicular to each other as electric fields vary sinusoidally over time
what are the names of mars' moons?
phobos and deimos
what are phospholipids made of?
phosphate group and two fatty acids
how do nucleotides bond with each other?
phosphate group of one nucleotide bonds covalently with sugar molecule of next nucleotide and so on
what are the four most common metabolic classifications?
photoheterotroph, autotroph, chemotroph, organotroph
how does the earth have oxygen when it originally had none?
photosynthesis - co2 gets converted into organic materials and oxygen
how do biologists classify life?
place them into superkingdoms called domains
what is an active region of the sun?
place where sunspots, flares, bright regions in chromosphere and corona tend to occur together
what is an elliptic plane?
plane on which a solar system orbits
list some potentially stable binary systems
planet orbits both stars, planet orbits 1 star
how does newton's second law affect planetary orbits around stars?
planet's mass = planet's acceleration(mass of planet/mass of star)
what can a light curve tell us?
planet's radius and thus volume
what can affect doppler motions at a very small level?
planet's speed
name the five main techniques for measure distance in the universe
planetary nebulae, cepheid variables, tully-fisher relation, type Ia supernovae, redshifts/hubble's law
what is the kepler-90 system?
planetary system most similar to ours
describe the contrast issue of direct detection
planets are fainter than sun
why are the internal structures of the giant planets so hard to predict?
planets are so large so interiors are so deep
what does the formation of deuterium result in?
process of fusing two hydrogen atoms together results in emission of a neutrino
how can a stable orbit be obtained in a binary star system?
planets must be very close to one star and far from the second, so that the second star will see the other star and planets as being a singular body since they're all so close to each other
what are rogue planets?
planets without stars
what makes plant cells unique from animal cells?
plant cells have a cell wall, chloroplasts, and a central vacuole, while animal cells don't
where do unsaturated fats and oils typically originate from?
plants
what are subduction zones?
plates colliding, causing one plate to force itself under the other or both plates to rise and form mountains
what is a rift zone?
plates pulling apart along a ridge, which may result in volcanic activity
describe the shape of a beta pleated sheet
pleats are caused by hydrogen bonding between atoms on the polypeptide chain's backbone
what is a radiant?
point in sky where dust particles and pebbles moving together in space come toward us; point were meteor streams appear to diverge
what creates auroras?
points where van allen belt intersects with the atmosphere
what is the most prominent surface feature on mars?
polar caps
describe the makeup of phospholipids
polar head with long nonpolar tail, thus making head hydrophilic and tail hydrophobic
what is a polypeptide?
polymer of amino acids
if a monomer is an amino acid, what is the polymer?
polypeptide or protein such as insulin
if a monomer is a monosaccharide, what is the polymer?
polysaccharide such as starch, glycogen, cellulose
what is the charge of a proton?
positive
what does pH stand for?
power of hydrogen/potential hydrogen
what is thermonuclear fusion?
power source of sun and most stars
what is translation?
process of making a polypeptide/protein from mrna
what does hydrophobic mean?
prefers exposure to oil - a nonpolar substance
what does hydrophilic mean?
prefers exposure to water - a polar substance
what do hot spots on venus indicate?
presence of huge shelf volcanoes emitting continuous lava flow
what could hot jupiters indicate?
presence of smaller planetary systems nearby
what could the crisscrossed ice patterns on europa indicate?
presence of thinner ice covering a global ocean; ocean could have warm springs, thus making it most likely place beyond earth to find life in our solar system
list the main winds and their directions on earth going from north to south
prevailing westerlies - west to east, northeast tradewinds - north to south, equator, southeast tradewinds - south to north, prevailing westerlies - west to east
describe the atmospheres of the giant planets
primarily composed of hydrogen and helium gas
why is protein denaturation often reversible?
primary structure of proteins is typically preserved
what are the 4 levels of protein structure?
primary, secondary, tertiary quaternary
what are the four levels of protein structure?
primary, secondary, tertiary, quaternary
what is evolutionary adaptation?
process allowing life to evolve based on its surroundings
compare polypeptide elongation in prokaryotes and eukaryotes
process is same
what is interstellar extinction?
process of absorbing/scattering light from nearby stars thru dust clouds, thus making stars look dimmer
what is gravitational collapse?
process of cold dense gas clouds collapsing in on each other to form stars; as dense gas clouds cool, gravity overpowers gas pressure, resulting in a positive feedback loop of collapse in which gravity contracts a lump of mass that results in pieces becoming closer together, amplifying gravitational force causing the contraction, and further accelerating the gravitational collapse; this feedback loop is an unstable runaway process until a new non-gravitational force builds up enough strength to balance inwards gravity
what is dynamo?
process of converting knetic energy into electricity
what is fusion in the context of a star?
process of converting one element into another
what is fluorescence?
process of converting uv radiation into visible light
what is semiconservative replication?
process of dna strands separating during replication to serve as templates for new strands
what is evolution?
process through which the characteristics of species change and through which new species arise - occurs through natural selection
what are metamorphic rocks?
produced when high temperature/pressure alters igneous or sedimentary rock physically/chemically
what is the force of attraction directly proportional to?
product of their masses
describe the nuclei of radioactive isotopes
prone to spontaneous change/decay, breaking apart,. or having one of its neutrons turn into a proton
list the stages of mitosis in order
prophase, metaphase, anaphase, telophase
who was jean-baptiste lamarck?
proposed incorrect but influential inheritance of acquired characteristics theory
what are exons?
protein coding sequences
what are reactions on the sun called?
proton-proton chain
what is a chromosome?
provides instructions for making precisely ordered chains of amino acids
what influences a planet's surface temperature?
proximity to sun and strength/size of atmosphere
what are the four possible tectonic plate reactions?
pull apart, one plate burrows under another, slide alongside each other, jam together
what is an electromagnetic spectrum?
range of electromagnetic radiation
why is finding ancient microfossils challenging?
rarity - oldest rocks are most likely to get altered by geologic processes
what is nuclear fusion?
reaction where heavier nuclei are created by combining/fusing lighter nuclei, which are all positively charged; however, electromagnetic forces cause nuclei to repel each other, so for fusion to occur nuclei must move fast enough to overcome that repulsion, which requires high temperatures and pressure
where does the mass from a supernova go?
recycled into space, becoming available to enrich gas and dust that go on to form new stars and planets
what are prominences?
red features high in sun's atmosphere
what is the 21 centimeter line?
refers to wavelength of energy required for an electron's spin to mirror that of its proton; allows astronomers to map out the gas in our galaxy
what are the basic properties of light that make all optical instruments possible?
reflection and refraction of light - lenses bend light while mirrors reflect light
what is the magnetosphere?
region of earth's magnetic field that extends into surrounding space - typically expands by 10 earth radii in sun's direction
what are plages?
regions in sun's chromosphere with higher temperature and density
what are eruptive prominences?
relatively rare; send matter up into corona at high speed
what is a comet?
relatively small chunk of icy material that orbits stars at extremely elliptical orbits; develops a tail as it approaches the sun
what happened to the missing mass in the hydrogen fusion process?
released as energy
describe the energy of a solar flare
releases total amount of energy equivalent to almost 1 million h-bombs; releases flood of x-ray and uv energy
how can some bacterial organisms live for centuries?
remain dormant for centuries then absorb water and resume growth after a period of no metabolism due to dehydration
what are comets?
remnants of solar system formation that orbit sun in distant cooler regions where dwarf planets are found
what is nucleotide excision?
repairs thymines that have been exposed to harmful uv rays
what is the baryon cycle?
repeating process of interstellar mass become stars than stars becoming mass again due to supernovae
what is the kepler telescope?
replacement of the first exoplanet detector - corot; regularly took images of 150,000+ stars for transit detection
what is the telomerase enzyme?
replicates and maintains telomeres
what are stromatolites?
rocks characterized by a distinctive layered structure; have layering caused by photosynthesizing organisms; provide indirect evidence of microbial life from 3.5 billion years ago; may also allow us to track evolution of photosynthesis
what are asteroids?
rocky bodies orbiting the sun like mini planets
what are the two distinct types of planets?
rocky terrestrial planets and gas-rich jovian planets
what is a solar nebula?
rotating cloud of vapor and dust from which the solar system formed
what is mercury's rotational period compared to its orbital period?
rotational period is 2/3 of its orbital period
how many stars does the milky way currently form?
roughly 1 star per year in its gas-rich spiral arms
what percentage of planetary systems have the transit alignment with earth?
roughly 1%
what is earth's diameter?
roughly 12,760 km
when did large continents begin to appear on earth?
roughly 2.7-2.5 billion years ago
what are the properties of super-earths?
roughly 2300 detected through the transit method; have high mean density when filled with rocks and metals and moderate mean density when filled with rocks and ice
how old is the sun?
roughly 4.5 billion years
how old is the earth?
roughly 4.55 billion years
what are enzymes?
roughly 4000 types; catalyze/speed up chemical reactions
when was fire invented?
roughly 5.1 million years ago
what is earth's radius?
roughly 6,378 km
what types of planets would be most ideal for life similar to ours?
small, terrestrial, same orbital period as earth, venus, mercury, or mars
list the orbitals in terms of energy from lowest to highest
s, p, d
how large can a comet's head become?
same diameter as jupiter
which planet has the lowest average density in the solar system?
saturn
which giant planets have four seasons?
saturn and neptune
what causes our sky to look blue?
scattering of sunlight through our atmosphere
what did the doppler method of exoplanet detection allow scientists to learn about exoplanets?
scientists could estimate their mass and sometimes learn about their atmosphere
what is a common piece of evidence of tectonic plate movement?
seafloor spread
what is helium like compared to hydrogen?
second simplest atom right behind hydrogen
where does the majority of earth's co2 come from?
sedimentary rocks such as limestone that formed in co2-rich oceans
describe the surface of titan
seems to be fairly similar to earth in size but is much colder with a thick atmosphere, lakes, rivers, falling rain
what is differentiation?
separation of densities - denser materials sink while lighter materials stay near the top
what is the primary structure of a protein?
sequence of amino acids that determines everything else about protein's final shape
what are introns?
sequences that don't encode functional proteins
how are the geological eras of earth's history assembled?
sequencing earth's ground layers - sedimentary rocks are laid down in a horizontal manner with younger rocks on top of older rocks
what is an emission spectrum?
series/patterns of bright lines consisting of light in which only certain discrete wavelengths are present
what is an absorption spectrum?
series/patterns of dark lines superimposed on a continuous spectrum - those dark lines are visible evidence of certain chemicals between us and a star
what is the quaternary structure of a protein?
several polypeptide chains being linked together in a single given protein
what are subunits?
several polypeptides that make up a single protein
why do many see chimps as good models of early humans?
share 96% of human dna
describe the genes of closely related organisms
share more genes
what are gamma rays?
shortest wave; carry lots of energy so is dangerous to humans
what is the coriolis force?
sideways force affecting air movement on earth's north-south meridian
what are stone meteors?
silicate/rocky meteorites
compare the volcanoes of io to earth's volcanoes
similar lava but io's volcanoes produce higher eruptive plumes due to frozen deposits of sulfur and sulfur dioxide around point of eruption
describe the surface of io
similar to earth's moon but is volcanically active as discovered by voyager spacecrafts with around 100 active volcanoes; also has volcanic pits
describe the interior composition of jupiter
similar to sun - mainly hydrogen and helium
describe neptune's appearance
similar to uranus but bluer due to scattering of sunlight in planet's upper atmospher
what is convergence?
similarity in form between distantly-related species as a result of adaptation to similar environments; in other words, these species have very different dna but similar traits
what are monosaccharides?
simple sugar; exist as linear chain or ring-shaped molecule
describe hydrogen
simplest and most abundant element
what do near binary stars appear as to those on earth?
single points of light
describe the structure of rna
single stranded polynucleotide molecule with ribose sugar and bases of either uracil, adenine, guanine, cytosine
what types of bonds can carbon atoms form?
single, double, triple; more bonds results in more strength
describe the first eukaryotic organisms
single-celled
what does the friction between earth and the moon cause?
slower planetary rotation - a day is longer by 1 second every 50,000 years as the conservation of angular momentum aka a slower spin from earth causes the moon to move farther away from earth
how fast do smaller stars burn fuel?
slowly
what are examples of irregular galaxies that are visible from earth?
small magellenic cloud and large magellenic cloud - satellite galaxies in the milky way
what is the nebular hypothesis?
solar and stellar systems were formed far from star beyond snow line before migrating inward or being collisionally scattered into orbits close to each other
what is the carrington event?
solar flare resulting in solar storm that reaches earth's magnetic field; as a result, aurora activity intensifies and becomes more widespread; led to speculation that solar activity can have impacts on earth
how did the solar system form?
solar nebula contracts and as nebula shrinks, its motions caused it to flatten; nebula became a disk of matter with a concentration near the center; this concentration becomes a protosun; other solid particles condense as nebula cooks to give rise to planetesimals - building blocks of planets
why is it important that water's liquid form is denser than its solid form?
solid water/ice can act as an insulator for the liquid water beneath it
why may we not be able to accurately study mars' geological history through images alone?
some of mars' geological history could be hidden under soil
how do microbes affect the health of our earth's atmosphere?
some play a vital role in cycling carbon and other elements between organic matter and soil and atmosphere
how does individual variation contribute to natural selection?
some variations in traits may cause some individuals to be better equipped to survive and/or compete for resources
why do older/more mature stars lack discs/rings?
something causes them to dissipate over time
what are meteorites?
space rocks that have survived the fall through earth's atmosphere
what are most earth-bound meteors associated with?
specific comets
how is the atmospheric makeup of the giant planets determined?
spectroscopic analysis
how does the sun have differential rotation?
speed of its rotation varies by latitude
what is the speed of electromagnetic radiation?
speed of light - therefore light is electromagnetic radiation
why can even such a small amount of mass result in a very large amount of energy?
speed of light^2 is such a large quantity
what is a pulsar?
spinning neutron steller remnant of a supernova
what type of galaxies does the tully-fisher relation distance measurement technique work with?
spiral
what type of galaxies does the cepheid variables distance measurement technique work with?
spiral and irregulars
what happens to a star after experiencing a triple alpha reaction?
star becomes a red giant again before decreasing in energy to become a white dwarf
what happens after all of a star's manufactured helium is depleted?
star contracts and continues to heat up
what are the four most common types of complex carbs?
starch, glycogen, cellulose, chitin
what did ancient beliefs say space was made out of?
substance called quintessence
where did all space dust in the milky way come from?
stars in the baryon cycle
what's the most common meteor class?
stone meteors - however are difficult to verify as extraterrestrial
what is glycogen?
storage form of glucose in humans and other vertebrates
what is starch?
stored form of sugar in plants
what is a strong interaction/strong nuclear force?
strength of force keeping atomic nucleus together
what is the build-up of helium dependent on?
strength of strong interaction
what is a poly-a tail?
string of roughly 200 adenine residues added to 3' end of dna after elongation process
describe the magnetic fields of the giant planets
strong with synchronation radiation because magnetic fields accelerate high speed electrons; magnetic field activity is similar to earth's van allen belt
what are covalent bonds?
strongest bonds formed when atoms share electrons
describe the temperatures of the giant planets during their formations
strongly heated due to their size
what is the secondary structure of a protein?
structural motifs such as alpha helix, beta pleated sheet, random coils
what is cellulose?
structural support for plants and other organisms; most massive type of complex carb
what is the tertiary structure of a polypeptide?
structure that determines its 3D shape
how did charles darwin find strong support for his natural selection theory?
studied artificial selection - the selective breeding of domesticated plants and animals by humans where most genes are the same but expression varies
how did scientists figure out what the center of the earth is like?
studied earthquake wave transmissions - since these waves can't travel through liquid, the waves were unable to travel to scientists on the other side of a planet from an earthquake due to the earth's liquid core
how did charles darwin prove evolutionary adaptation?
studied galapagos island finches
how can we determine a star's orbital speed?
study doppler shifts in its spectrum
what is geology?
study of earth's crust and processes that have shaped its surfaces throughout history
what is quantum mechanics?
study of how particles act like waves
what is comparative anatomy?
study of similarities and differences in morphology
what is comparative terrestrial planetology?
study of terrestrial - rocky - planets thru comparing them all
how can scientists detect stellar wobble
studying doppler shifts
what are the basic techniques of planet hunting?
studying faint, barely perceptible variations in a star's light as a planet orbits in front of it
how can interstellar dust substances be exactly identified?
studying meteorites
how can we learn about what original plantesimals were like?
studying primitive meteorites
how was the orbital period of 51-pegasus determined?
studying repetitive ~4 day period of star's motion
how can exoplanets be detected?
studying small shifts in spectroscopic binary of a single star caused by the exoplanet's mass
what are bases?
substances accepting H+ ions/protons
how can mass extinction be detected through the study of rock layers?
sudden disappearance of multiple species between different layers
what is the missing link in the fossil record?
sudden jump in fossil record from one species to another brand-new species; didn't happen to all species; links can only be filled as more fossils are found
what did the clementine spacecraft find on the moon?
suggestions of ice at the south pole in craters
what type of element is most common on io's surface?
sulfur - condenses easily and appears black when heated
what is atomic number?
sum of protons
what is atomic mass?
sum of protons + neutrons
how is the brightness of galaxies determined?
take brightness of stars in each thin "shell" of light reaching earth; more distant shells will contain more stars, exactly cancelling out their greater distances
what are faults?
tectonic plate boundaries
what would we need to tell extraterrestrials about if we were to ever interact with them?
tell them about our culture, art, social/survival instincts, capability to harm/kill others, politics, atomic weaponry, technology, current scientific knowledge
what is an example of reddening on earth?
sun looking redder at sunset
how has our habitable zone changed over time?
sun's 30% increase in luminosity has pushed out our habitable zone by 15%
what drives solar activity?
sun's changing magnetic field
what is responsible for the strength of the sun's magnetic field?
sun's dynamo - as the fields from its dynamo interact, they break, reconnect, and rise through the sun's surface
what types of planets are we discovering that our solar system doesn't have?
super earths and mini neptunes - planets between the sizes of earth and neptune
how does dna fit into a single cell?
supercoiling
what is pangea?
supercontinent on earth 230 million years ago
where did some of the heaviest elements in the milky way likely come from?
supernovae
how can elements heavier than iron be formed in space?
supernovae ejecting neutrons could be absorbed by iron
what do scientists believe the source of heat energy heating hydrogen gas in space is?
supernovas
what are the unique features of earth most important for life?
surface liquid water, atmospheric oxygen, plate tectonics, climate stability
how can space dust facilitate the production of other compounds?
surfaces of grains have nooks for atoms to get stuck in when grains freeze; the heat of stars forming within dust clouds will evaporate the ice on the grains and free new compounds
why is io dangerous to approach?
surrounded by strong radiation
what is the penumbra of a sunspot?
surrounding, less dark region
what are thermophiles?
survive at high temperatures
what are psychrophiles?
survive at low temperatures
what are deinococcus radiodurrans?
survive under high radiation
what is the periodic table of the elements?
table for arranging elements based on their characteristics
what is a common determiner of the type of electromagnetic radiation being emitted by objects?
temperature, since it's a measure of average motion energy of particles making up an object
what is convergent evolution?
tendency of organisms with vastly different genetic backgrounds to evolve similar traits
where is convection common?
terrestrial planets, gas giants, sun, all stars
what are the three main types of steroid lipids?
testosterone, estrogen, cholesterol
how is the orbital distance of an exoplanet measured?
through doppler or transit methods - we calculate orbital distance from orbital period using newton's version of kepler's third law
how does a gas's color relate to a star's color spectrum?
the color it emits would be the same color it absorbs on a star's color spectrum
give a real life example of ε
the fuel powering our sun converts .7% of its mass into energy when fusing into helium
describe the movement of waves from a point of origin
travel rapidly outward from point of origin and use energy to disturb things farther away
how does the strength of covalent bonds increase?
the more electrons that atoms share, the stronger the bond
describe mars' atmosphere
thin, filled with co2, experiences little greenhouse effect due to its lack of gravity
describe europa's atmosphere?
thin, mainly oxygen
what causes the vaporization of meteors?
their friction with the air
how do we know that a meteorite is primitive?
their ingredients are simple
why can electromagnetic waves travel through a vacuum?
their movements are triggered by only each other; they all move at the same speed in vacuums, too - speed of light
why are the noble gasses some of the most stable atoms?
their outer shells are full
what is the breakup hypothesis?
theory that planets' rings come from shattered moons
what is the reverse breakup hypothesis?
theory that ring particles were particles unable to form a moon
what's the most dismal potential result of seti?
there's only one intelligent species in the solar system - us
list the most common types of extremophiles
thermophiles, psychrophiles, deinococcus radiodurrans, endoliths
how can elements numbered beyond 100 exist?
they can't - only in manufactured scenarios
why are our oceans rich in co2?
they dissolve carbon dioxide and lock it away near the floor
why do astronomers study differences in the shapes of galaxies?
they hope to discover that differences in their appearances have to do with differences in how galaxies evolve
how do positrons create electromagnetic energy?
they instantly collide with a nearby electron since positrons are antimatter, annihilating both particles and producing strong electromagnetic energy in the form of gamma-ray photons - those interactions keep happening in the sun until they reach its outer layers, where they weaken and become x-rays
what happens when a proton and electron in a star's core merge?
they make a neutron and merge releases a neutrino
how do large moons help sustain life?
they stabilize earth's obliquity/tilt, keeping it within the narrow angular range; without the moon, the obliquity angle would chaotically vary between 0 and 85 degrees
what are the problems with directly detecting exoplanets?
they're hard to see due to contrast issues and angular resolution
what's the significance of hot jupiters?
they're proof that planetary migration is possible
why are UFOs a poor indicator of intelligent life?
they've never actually belonged to extraterrestrials
describe venus' atmosphere
thick perpetual cloud cover that makes observing venus' surface difficult
what was the 1st planetary system found?
upsilon andromedae in 1999
why is counting impact craters sometimes an inaccurate method for aging planets?
this only tells us about the time since a surface had experienced a major change that could modify/erase preexisting craters
to darwin, what was natural selection an inevitable outcome of?
three principles in nature: characteristics of an organism are inherited, more offspring are produced than are able to survive, offspring vary among each other in characteristics and variations are inherited
how is an exoplanet's mass measured?
through doppler method - calculated based on amount of stellar motion caused by planet's gravitational tug
how is an exoplanet's orbital inclination measured?
through transit method - can only be done for edge-on orbits
how is an exoplanet's size/radius measured?
through transit method based on amount of dip in a star's brightness
how is an exoplanet's atmospheric composition and temperature determined?
through transit method or direct detection
how is an exoplanet's density measured?
through transit or doppler method by dividing mass by volume
how are electron orbits studied?
thru quantum mechanics
why does io have no water or carbon dioxide?
tidal heating and slightly eccentric orbit drove it away
describe mars' axis
tilted like earth's - therefore has similar seasons and has polar caps
what is a half life?
time for half a substance to decay by radioactive processes; though a particular nucleus may last longer or shorter than its half-life in a large sample, almost exactly half of the nuclei will have decayed after a time equal to one half life
what is a meteor?
tiny solid particle entering earth's atmosphere from interplanetary space
what is saturn's largest moon called?
titan
compare titan's atmospheric density to earth's
titan's density is 4x greater than earth's
why do scientists study the habitable traits of earth?
to know what's typical of habitable planets and what makes them unique from other planets
how do stars evolve after their cores exhaust themselves of hydrogen?
to maintain pressure balance, gravity condenses and heats star's core; when hydrogen runs out, core will continue to condense; interior will heat up as surface cools; hydrogen fusion can now occur powerfully in a shell, turning a star into a red giant
how are dust clouds detectable?
too cold to radiate a measureable amount of energy in the spectrum but can glow infrared brightly
why are comet nuclei difficult to study?
too small and dark to be studied from earth
what is convection?
transferrence of energy from a warm region to a cooler region
when does translation begin?
trna anticodon recognizes a codon on mrna; large ribosomal subunit then joins small subunit and second trna joins; as mrna moves relative to ribosomes, polypeptide chain begins to form
what is a simple sugar made up of?
two glucose monomers
describe the structure of dna
two linked chains of nucleotides packaged into a chromosome
what are molecules?
two or more of atoms held together by bonds
explain the process of thermonuclear fusion
two protons get close enough together to stick by overcoming electric force's repulsion via the uncertainty principle; later, a 3rd proton sticks on, making tritium; finally, a 4th proton hits to make helium-4; along the way, 2 protons are converted into positron + neutron + neutrino
how can exoplanets be discovered through studying gravitational interactions?
two techniques - astrometric method and doppler method both rely on observing the motion of the star caused by small gravitational tugs from orbiting planets; center of mass of a planetary system can be thought of as fulcrum on a see saw that the other planets orbit around - this center is usually the sun
how is a stable He formed from ³He?
two ³He, which requires 3 H each to form, must be combined
what is trna?
type of rna molecule that brings amino acids to the growing polypeptide chain; are adaptors that bind to sequences of mrna before adding an amino acid
what is transfer rna?
type of rna that carries each amino acid to a ribosome during protein synthesis; floats freely in cytoplasm with amino acids; also collects amino acids for dna synthesis
what is the function of amino acid sequences?
ulimately determine protein's shape, size, function
what are the two parts of a sunspot?
umbra and penumbra
how common are large asteroids?
uncommon since they're so prone to being broken up by collisions
what is gravity?
universal attractive force between all masses
what are the implications to solving olber's paradox?
universe and its contents must have evolved from a smoother simpler state to its current complexity
what does hubble's law prove?
universe is expanding
why has no simple scheme for evolving one type of galaxy been found?
unpredictable collisions can affect shape
what are meteorite finds?
unusual looking rocks that turn out to be meteoritic
how long did life exist in oceans before moving to land?
up to 3.8e+9 years
how hot can high mass stars get?
up to 6e+8 K as C fuses into O
what does a triple alpha reaction do?
uses hot helium from hydrogen fusion and high densities to promote collisions enough time for three helium nuclei to hit each other simultaneously and create a special excited state of the carbon-12 nucleus
why does venus have no water molecules?
uv light from sun broke them all up
how is eq expressed numerically?
value normalized to 1 where species above this value are considered more intelligent
what are cepheids?
variable stars - can be used to measure distances to other galaxies
describe martian weather
varies greatly by season due to the absence of regulating oceans and clouds
what's the third-brightest object in the sky?
venus
how common are exoplanetary systems?
very - 10-50% of stars could have 1+ planets
compare saturn's overall atmospheric structure to jupiter's
very similar but colder
what are the robotic missions that have searched for life on mars?
viking, pathfinder, rover, spirit, opportunity
describe venus' magnetic field
virtually nonexistent due to its slow movements
what do dust clouds look like when seen through a telescope?
voids of nothing - clouds betray their presence by blocking starlight, emitting infrared energy, reflecting light of nearby stars, or by making distant stars look redder than they really are
what types of craters does io have?
volcanic craters - means that io has active volcanoes
which spacecraft confirmed the atmospheric makeup of jupiter and saturn?
voyager
what happens to excited hydrogen atoms if they experience no collisions in space?
waits 10 million years to emit a photon and neutralize again
what was young mars' climate like?
warm and wet
what is local fluff?
warm cloud of interstellar matter that sun entered roughly 10,000 years ago
how is dna related to rna?
was likely a mutation of rna since dna cannot operate without rna
how did the universe become heterogenous?
was original extremely uniform, but small differences in density of dark matter expanded with the universe to the point of the creation of structures
how did the sun form?
was originally a cloud of gas undergoing gravitational collapse; eventually formed a core that got hot and dense enough to star nuclear fusion reactions; once the reactions begun, they generated enough energy to provide an outward pressure to keep the sun stable, thus creating a constant equilibrium between pressure and gravity
what molecule can life not exist without?
water
where is the majority of oxygen in living cells found?
water molecules
what does the presence of gullies on mars tell us?
water still occasionally flows on mars today, since the gullies are young with surface patterns that change seasonally
what does redshift and blueshift mean to a viewer?
wavelength will appear to change depending on your perspective on the wave, however sideways motion doesn't cause this doppler effect
how can observation of a star's movements help us find exoplanets?
we can observe the effect that a planet emits on its host star; these effects are usually seen as a wobble and happen since gravity is a mutual attraction with unequal forces exerted between two different sized objects
why are x-rays bad for us?
we can't re-emit all of their radiation in the way that we can with photons
what is a hydrogen bond?
weak attraction between a hydrogen atom and another atom; form slightly positive and slightly negative charges of polar covalent molecules
describe the solution to olber's paradox
we cannot receive photons from infinitely far away, because there has only been a finite amount of time for them to travel; our universe hasn't been producing starlight for an infinitely long time back into the past, therefore, the universe must have evolved at some point. in other words, the universe wasn't always capable of emitting starlight
describe humans' relationship to monkeys and apes
we didn't evolve from them - they're all modern species; however, both had common ancestor in distant past
describe the kepler-90 system
we don't have technology to know what these planets look like - we only know that their sizes are relative to their star
how do we know the age of the solar system?
we studied decay of heavier nuclei
how can hubble's law be used to find distance?
we use a spectrum to measure speed at which the galaxies moves away from us, so using this speed and hubble's constant, we can solve for distance using the hubble's law equation - d=V/H
what plays a major role in sculpting the martian surface?
wind erosion
what is the san andreas fault?
where pacific plate and north american plate meet - one plate is traveling north while the other goes south, and those conflicting movements create an occasional release of pressure between the faults in the form of earthquakes
what is the local bubble?
where the sun is - filled with hot x ray emitting gas
what is a type Ia supernova?
white dwarf exploding in a binary system that could provide accurate measurements for standard bulb lumosity
what can researchers not conclude about the sun's magnetic field?
why it changes
what is the cassini division?
wide gap between a and b rings
what does the evolution of intelligence enable?
wider variety of behaviors to meet changing situations such as predator-prey relationships or social habits
what will happen after the sun runs out of energy?
will expand and brighten into a red giant
where did the local bubble likely come from?
winds from stars and supernova explosions
where is dna found?
within all living organisms
does uranus have any rings?
yes - 11 rings
does saturn have any rings?
yes - broad, flat, large
does jupiter have any rings?
yes - they're faint
did the earth experience a period of heavy bombardment?
yes - we just can't see its craters because its weather/tectonic plates have made them practically disappear
for what types of planets does the direct imaging method work best?
young gas giants since they usually emit infrared light and reside at large separations from their host star
what is the oldest known material on earth?
zircon crystals aged 4.38 billion years - found in western australia
summarize the sun's nuclear reactions for energy production
¹H+¹H→²H+e⁺+v, ²H+¹H→³He+γ, ³He+³He→⁴He+¹H+¹H where superscripts=total number of neutrons+protons in nucleus, e⁺=positron, v=neutrino, γ=emission of gamma rays
what is the formula for wien's law?
λmax = 3e+6/T where T= temperature
what are the six numbers essential to the universe?
ℵ, ε, Ω, λ, Q, D
how can the relative speed of an observer and a source in line of sight be determined?
∆λ/λ = v/c where ∆λ=difference between actually wavelength and wavelength measured by observer, λ=actual wavelength, c=speed of light, v=relative speed of observer and source in a line of sight
