Astronomy Finals
In what way is the universe growing in size each day?
-universe is constantly expanding (larger than when you woke up this morning) -rate of expansion is accelerating -the most distant galaxies are moving away from us faster than the speed of light (new space is pouring in)
Describe 4 ways you are moving through space even when sitting perfectly still.
1) moving about 700 mph b/c Earth's rotation 2) moving at 66,000 mph bc Earth's revolution around Sun 3) Sun revolves around core of Milky Way galaxy at 483,000 mph 4) drifts towards the Mysterious Great Attractor at 1.4 mil mph 5) moving 1 mil mph b/c cosmic radiation
Which of Newton's Three Laws explains: why rockets are staged?
Law 2
What causes the sky to be blue during the day?
The atmosphere scatters the colors in sunlight one by one, beginning at the violet end of the spectrum. When the Sun is high in the sky, only the violet, indigo, blue and a little green are scattered, producing a blue sky
What is the difference between revolution and rotation?
When an object turns around an internal axis (like the Earth turns on its axis), it is called a rotation. When an inject circles an external axis (like the Earth circles the sun) it is called a revolution.
Why is the Moon not considered a possible habitat for an alien microbe?
The Moon is lifeless: it contains no living organisms, fossils, or native organic compounds
Where is the Sea of Tranquility and Tycho's Crater on the Moon?
ADD BETTER IMAGE HERE!
What causes day and night? A year?
Earth rotation =day/night Earth revolution = year
How do astronomers estimate the number of galaxies in the universe?
-count in square and extend it (Hubble Space Telescope)
What are some of the impacts of light pollution on human health and wildlife?
-throws off circadian rhythm (suppresses melatonin which is a tumor repressant) -endangered species (birds and turtles)
Which Apollo mission saw the first humans in orbit around the Moon, land on the Moon, and which was aborted b/c an oxygen tank exploded?
First Humans in Orbit: Apollo 8 Land on Moon: Apollo 11 Aborted: Apollo 13
Which of Newton's Three Laws explains: rockets work just fine in the vacuum of space?
Law 3
Which of the following objects work as intended on the surface of Mars: electric vehicle?
yes, battery-powered/charge up
Explain how Earth got its Moon (Giant Impact Theory).
-early Earth did not have a moon -4.5 bya, a giant planet impacted Earth (Theia) -the collision was a glancing blow that cleaved off only a portion of Earth's rocky mantle -mega collision resulted in a large ring of debris flying into orbit around the Earth -over time, the debris ring coalesced and formed the Moon
Explain the significance of each of the following NASA projects: DAWN.
-first time visited asteroids in Asteroid Belt
What are two reasons Oumuamua captivated astronomers?
-first visitor from outside of our solar system -not comet/asteroid b/c moves much slower -no radio signal detected -unusual path
What are the four types of robotic space missions?
-fly by (leave Earth, no orbit, just flying by) -orbiter -lander (touch down on surface) -rover (land and explore)
Why do astronauts on-board the ISS appear to float?
-freefall (keeps falling around Earth)
What two factors contribute to full Moons that look extra large?
-in comparison to other objects -zooms out and makes the Moon look bigger -blows up the image of the Moon -perigee (literally closer) -lower in sky, looks bigger (on horizon)
What are some of the major health/safety concerns associated with space travel?
-muscle atrophy -bone loss -loss of pressure -lack of oxygen -need to remove carbon dioxide from E ELABORATE!
At what cardinal points does the Sun rise on March 21, June 21, September 21, and December 21? Also, in which direction does the Sun's position at sunrise shift after those dates?
-north, south, east, west -due east on first day of spring (March 21) and first day of fall (Sep 21) -south = dec 21 -north = june 21
What are some of the key differences between the old moon rocket (Saturn V) and the new moon rockets (SLS)?
-powerful, staged SLS: more powerful, can hold more people -recyclable parts
Why do we see the Sun before it actually clears the horizon in the morning and after it sets in the evening?
-refraction
Identify the roles of each of the following vehicles/spacecrafts in terms of eventually sending humans to Mars: space launch system.
-rocket to take humans to Mars called the Space Launch Systems (SLS)
Explain the significance of each of the following NASA projects: New Horizons.
-sent us the first pics of Pluto and Moons -found out that has atmosphere and has ice volcanoes
Describe the process of differentiation.
-shows that it is not a primordial object (or one that stays in the same state) b/c internal movement (layering) has occurred through organization of layers where the densest materials sink to the core
What evidence supports the Giant Impact Theory?
-similarities in Moon and Earth rocks: 98% of minerals same -chemically similar -formed close in nebula -moon has smaller iron core, didn't form in same region so impact - sideways impact
Identify the roles of each of the following vehicles/spacecrafts in terms of eventually sending humans to Mars: orion space capsule.
-space capsule will be placed on top of the SLS and will carry astronauts from Earth to Mars -has three main parts: launch abort system, crew module, service module
What are some of the indicators that one is seeing a satellite and not an airplane?
-speed it is moving at (2 min across the sky) -white light? -steady light (not blinking?) -no sound (b/c in freefall) -usually seen a couple of hours before or after sunrise/sunset)
Explain the statement: "when we look into the sky, we are looking back in time."
-telescopes are time machines -b/c great distances in space, there's always a considerable delay between when an astronomical object emits light and when we receive the light here on Earth (light is not simultaneous) -takes time for light to travel (seeing light of the past)
Provide 5 good arguments as to why astrology is not credible and why it is not a science.
-there is no mechanism (astrologers usually point to gravity as the force that could act over the great distances in space and influence objects on Earth)
Which of the following objects work as intended on the surface of Mars: walkie-talkie?
yes, radio waves
Why does the Moon have a far side?
b/c gravitational lock so can only see the same face of the Moon
What were the key steps in the Apollo flight plan?
launch, Earth orbit, trans-lunar injection, lunar coast, lunar insertion, lunar orbit, lunar landing, lunar take-off, command module-lunar lander docking, trans-earth insertion, earth coast, touchdown
Which of the following objects work as intended on the surface of Mars: alarm clock?
no, b/c can't hear in space (no sound)
Which of the following objects work as intended on the surface of Mars: kite?
no, no air
Which of the following objects work as intended on the surface of Mars: airplane?
no, nothing could fly
What does it mean to say that space is bendable and flexible?
spacetime can twist, bend, distort and can ripple due to gravity waves
What is the rotational rate (if any) if the Moon?
takes 27 days to rotate on its axis which aligns with the period of one revolution
Which of the following objects work as intended on the surface of Mars: flashlight?
would work (battery)
In what important way is the dimension of time different from the 3 other spatial dimensions?
A dimension is a possible direction of movement. It is different from the other dimensions b/c you can only move forward (only travel through it one way) -a dimension b/c in order to define the exact place in spacetime you gave to fully describe the positions through x,y,z and time -can only move one direction through time
Why do astronomers suspect that dark matter exists?
A form of matter that exerts gravity and there's no interaction between it and regular matter. We know it exists b/c stars at rims of our galaxy wouldn't be able to stay in orbit without it b/c they spin at such high speeds so dark matter must be what holds it stable. -stars out there, should be all flung away-gravity used to keep in check
What is the Great Cold Spot and one intriguing theory as to its nature?
A large region at the formation of the universe that is colder than the surrounding regions and a possible explanation that our universe in connected to a multiverse (there's only a 2% chance that it's a fluke)
What is a transit? What planets can transit the Sun as viewed from Earth?
A transit occurs when an inner planet passes in front of the Sun - as viewed from Earth. Mercury and Venus can transit the Sun as viewed from Earth.
If provided a sketch of the solar system, identify the locations of the Oort Cloud, Kuiper Belt, and Asteroid Belt.
ADD PIC
Explain the shape of the light curve for an eclipsing binary star. INSERT CHART FROM GRAPH
ADD PIC -dips caused by star passing in front of another star -no dips=side by side -small star eclipsed=small drop
Explain the significance of each of the following NASA projects: Juno.
Allowed us to study the polar regions of Jupiter -found hundreds of small cyclones at the poles of Jupiter
What factors (perihelion/aphelion and apogee/perigee) favor annular eclipse?
Apogee (Moon further away in orbit) PERIHELION
Compare the relative distances that the following objects are from Earth: Sun, Mercury, Mars, Jupiter, Pluto, Proxima Centuari, Heart of Milky Way, Andromeda Galaxy.
Closest to furthest: Mars, Mercury, Sun (interchangeable), Jupiter, Pluto, Proxima Centuari, Heart of Milky Way Galaxy, Andromeda Galaxy
Define the term "parallel universe."
Level 1 Parallel Universe: exists in the same space-time as our universe and would be born in the same Big Bang - would be the gazillion of other universes beyond the horizon of the observable universe = the "rest"of the universe *more to universe than we can see* -other universes that we can't see
Explain the difference between a Level 1 and Level 2 parallel universe.
Level 1: exists in the same space-time as our universe and would be born in the same Big Bang - would be the gazillion of other universes beyond the horizon of the observable universe = the "rest"of the universe (extension of ours), just can't see it) Level 2: our universe is in effect a multiverse-a huge eternally growing fractal consisting of many different universes
Define "astronomical unit" and "light year" and know the appropriate setting for each term.
Light year: the distance light travels in a year (measures distances between stars) AU: distance from Earth to Sun (measures distances within solar system)
Order the following wavelengths in order of increased energy: ultraviolet, infrared, gamma, radio, X-ray, visible, and microwave.
Low energy to increased energy: Radio Microwave Infrared Visible UV X-ray Gamma ray
Compare and contrast: quasar v. galaxy
Quasar: highly energetic core of a remote active galaxy; the most luminous objects in the universe, capable of radiating a trillion times as much energy as Sun in area as small as solar system Galaxy: great cities of stars in space containing a few hundred million to a few trillion or more stars held together by gravity and orbiting a common center
What telescope is on the ground based on atmospheric windows?
RADIO, only one that passes through atmosphere
What causes the seasons?
The seasons are caused as the Earth, tilted on its axis, travels in a loop around the Sun every year. Summer happens in the hemisphere tilted towards the Sun, and winter happens in the hemisphere tilted away from the Sun
What is Earthshine?
The unlit portion of the moon ofter appears to glow due to reflected light from the earth -get up early in morning, crescent -Earth light hitting and illuminating part of the Moon
What are spin-off products? What are some examples?
Whenever a problem for astronauts, inventions are created and then used in the real world EX: memory foam, cordless tools, modern insulation, CAT scan, water filters, ear thermometers
Why doesn't Pluto meet the definition for a planet?
-didn't clear out its orbit -Kuiper Belt
Compare and contrast: black hole v. neutron star v. white dwarf
*ALL TYPES OF DEAD STARS* Black hole: remnants of the MOST MASSIVE stars -they have the masses of several Suns, but have an infinitely small volume Neutron star: wildly hot and dense cores of LARGE stars White dwarfs: extremely hot and dense cores of dead MID-SIZED stars such as the Sun
Why were V2 rockets important in the history of rocketry?
-*first large scale rocket* developed by the Germans as weapons in WW1 -one of the german scientists became the leading scientists in designing the rockets that would help America reach the Moon
What was the scientific purpose of launching chimpanzees into space in the 1950s?
-TEST FOR COGNITIVE ABILITY -even if in space (acceleration)
What two factors determine the size and boundaries of the observable universe?
-age of the universe -speed of light
What are some of the positive steps that could be taken by those interested in reducing light pollution?
-all street lights fully shielded -motion sensing lighting -one way glass -turn lights off at night -ban billboards (b/c lights pointed upwards)
What happens the sun to appear red at sunrise and sunset?
-blue doesn't survive to the surface, so appears red Sunsets are red b/c blue and violet beams completely scattered when they must transverse a lot of the atmosphere, so only red/orange/yellow survive to the surface
Identify the roles of each of the following vehicles/spacecrafts in terms of eventually sending humans to Mars: lunar gateway.
-check in point where they can refuel (space station around Moon) -space station around Moon
Why do astronomers believe that planets nine and ten exist?
-dark, doesn't give off light so we cannot actually see them -know they are there b/c ice bodies and the objects we see in the Kuiper Belt appear to be gravitationally disturbed -objects in Kuiper Belt (weird tug/pattern in objects - presence of other objects=same way they found NEPTUNE)
Describe the possible role of the Moon in controlling wind speeds on Earth, encouraging the development of life on land; assuring that seasonal variation are stable over the course of thousands of years.
1) no terrestrial life -tides pushed life forms onto land (emergence of terrestrial life forms) 2) normal winds -frictional forces on floor of Earth's oceans-Moon slowed down rotation rate=created normal winds 3) normal atmosphere -collision w/ Theia boiled away part of Earth's atmosphere -the original was thick w/ CO2 -development of life would take longer than it already did 4) stabilized tilt -moon stabilizes tilt (22-24 degrees wobbling range) -seasons stabilized (consistency instead of extremes) -plants and animals can adapt
What are Newton's Three Laws?
1) stay in motion unless force acts upon it 2) more force=more velocity; less mass=more velocity 3) action=reaction, equal and opposite force
Why are the solar eclipses of 1868 and 1919 especially notable to scientists?
1868: discovered the telltale signs of helium in the Sun's corona (first chemical element to be discovered outside the Earth) 1919: used to prove Einstein's theory of relativity by showing that gravity can bend light (the Sun's mass was sufficient enough to warp space-time and light rays emanating from stars behind the Sun)
What is the origin of space junk? and why is it a concern to NASA and other space agencies?
20,000 objects in space in orbit around Earth that are 10 cm or longer (we put it there) -HUGE PROBLEM: if it hits anything b/c so dangerous since moves so fast -any collision with astronaut, spacecraft, or satellite=high damage -caused b/c just leave remnants in outer space and blowing up asteroids, and such
Which of Newton's Three Laws explains: why it is important to keep the mass of rockets low?
Law 2
Compare and contrast: asteroid v. comet
Asteroid: Small, rocky bodies in orbit around the Sun (found in asteroid belt between Mars and Jupiter), can be really big (up to 1000 km) -rock and metal, no tail Comet: relatively small, icy bodies in orbit around Sun (found in outer solar system) -ice, rock, hydrogen, carbon, tail
Compare and contrast: cosmology, astronomy, and astrobiology
Astronomy: study of stars, planets, and the objects in outer space Cosmology: study of the origins and the structure of the universe Astrobiology: study of prospective life-forms elsewhere in the universe
Compare and contrast: brown dwarf v. main sequence star
Brown dwarf: intermediate mass between a star and planet and are sometimes described as "failed stars" b/c not massive enough to have initiated hydrogen fusion Main sequence star: giant sphere of plasma that produces heat and light by nuclear fusion (hydrogen to helium) and differ in mass and temperature (blue=hot and massive; red=cooler and less massive)
Why do astronomers believe that dark energy exists?
Dark energy is the driving force that is causing the universe to get bigger at an ever increasing rate. b/c there has to be a force stronger than gravity pulling the universe outward -no force can explain expansion of universe and at accelerating rate
What are maria? How did they form?
Dark spots "oceans" on the Moon (roughly circular) -series of huge asteroid impacts created basins on the cooling Moon's surface -these collisions cracked the surface and lava oozed up and filled those cracks
Compare and contrast: dwarf planet v. planet v. moon
Dwarf planet: planet-like objects that meet the following requirements: -in orbit around the Sun -nearly round shape (due to sufficient mass for self-gravity) -not cleared out its orbit -not a satellite/moon Planet: moderately large objects that orbit stars -directly orbits a star -spherical -cleared out its orbit Moon (or satellites): objects that orbit a planet
Write a cosmic address for yourself (include the solar system, milky way, local group, and laniakea supercluster)
Earth Solar System Milky Way Galaxy Local Group Laniakea Supercluster Observable Universe Multiverse
Explain the term "atmospheric windows" with respect to wavelengths that reach Earth's surface.
Earth atmosphere does not allow many types of radiation to reach Earth's surface: Gamma/x ray -RADIO AND VISIBLE LIGHTS GOING THRU WINDOWS
What is perihelion and when does it occur?
Earth closer to the sun, occurs on January 4th
Compare and contrast: exoplanet v. rogue planet
Exoplanet: planets that orbit stars other than the Sun Rogue planet: (or orphan/nomad planets) orbit the galaxy directly (they do not orbit individual stars)
Define the "habitable" zone and offer a criticism of the term.
Habitable Zone: area around star where temps are not too hot and not too cold (liquid water should exist on the surface) -do not know if this is the only condition where life can exist (chemosynthesis in frozen ocean and volcanic core (energy source))
Explain the genesis of the following atoms: hydrogen, helium, carbon, and iron.
Hydrogen/helium: all made in Big Bang-made from pure energy in the explosion (helium also made w/ fusion in the Sun) Carbon: exposing massive stars/dying low mass stars Iron: exploding massive stars/dying low mass stars
Compare and contrast: interstellar space v. intergalactic space
Interstellar space: space between stars (density of atoms here is very low=less than 10 atoms/cubic cm) Intergalactic space: space between galaxies (density is extremely low=less than 1 atom/cubic cm)
Why does the Moon lack an atmosphere?
Its atmosphere escaped into space due to the low surface gravity of the Moon (could not retain air)
Which of Newton's Three Laws explains: why rockets can coast for most of the journey to the Moon (or Mars)?
Law 1
Which of Newton's Three Laws explains: why launch sites near the equator are best?
Law 1 (rotational assist)
Compare and contrast: meteor v. meteorite v. meteoroid
Meteor: small bits of dust/ice/sand that enters the Earth's atmosphere (burn up before reaching Earth's surface Meteoroid: Small rocky/metallic body in orbit around the Sun Meteorite: objects from space captured by Earth's gravity and survives passage through Earth's atmosphere
What is a molecular dust cloud?
Molecular dust cloud (nebulae): -regions in space w/ higher densities of gas and dust where new stars are born
What are three differences between globular star clusters and open star clusters?
Open cluster: -blue = young -used to be molecular dust cloud -less stars and less densely packed together -disk close to us Globular cluster -orange (lots red giants=more evolved) -more stars and more densely packed together -outer halo
Explain the significance of each of the following NASA projects: Cassini.
Sent us images and data from Saturn and its moons -found out: geysers on Enceladus (liquid underneath the surface)
Explain the significance of each of the following NASA projects: Voyager 1 and II.
Sent us the first images of outer planets and moons (close-up) -found out that Europa has ice sheets (oceans underneath) and active volcanoes on Io -all first outer planets
What are some of the differences between solar and lunar eclipses?
Solar: -occurs during the day -need eye protection -takes 2-5 min -New Moon phase -small fraction of the world can see it Lunar: -night -no eye protection -half of the planet can see it -several hours -Full Moon -moon blocked
Why was Sputnik a big deal?
Sputnik 1: -first artificial satellite into low Earth orbit -beat US to important milestone=technologically inferior political rival, also now worried Soviets could deliver weapons across the ocean Sputnik 2: -dog blasted in Earth's orbit
Why is "observable" often added as a qualifier when discussing the universe?
The observable universe is the part of our universe that we can see. Presumably, there are parts of our universe we cannot see simply b/c the universe isn't old enough to have allowed light to have reached us from all areas
What are three types of solar eclipses?
Total eclipse: occurs when the Moon passes in front of the Sun; as the Moon's shadow falls upon the Earth, those is the umbra (the deepest part of the shadow) witness day turning into night Annular Eclipse: occurs when the Moon passes directly in front of the Sun, but isn't large enough to completely cover the Sun's disk Partial Solar Eclipse: happens when the Moon passes in front of the Sun, but it is off-center, so doesn't completely block the Sun