Astronomy Midterm UCLA

Coepernican heliocentric model

It positioned the Sun near the center of the Universe, motionless, with Earth and the other planets orbiting around it in circular paths modified by epicycles and at uniform speeds.

What are the advantages of putting telescopes in space?

putting telescopes in space can alleviate the atmospheres turbulence It allows us to observe light that does not penetrate Earths atmosphere

Speed of light and how to calculate it

186,000 mi/s 300,000 km/s Speed= distance/time

The daily and annual motion of stars in the sky

"Rise in the east and set in the west" The night sky changes throughout the year because of Earths changing position in its orbit around the sun causing stars to "move" to different places in the sky

Newtons laws Of motion

1. In the absence of a net force, and object will move with constant velocity. Objects at rest tends to remain at rest and object in motion tends to remain in motion with no change in either their speed or their direction. 2. Force equals mass times acceleration. 3. Every force is always paired with an equal and opposite reaction force

Kepler's three laws of planetary motion

1. the orbit of each planet about the sun is an ellipse with the sun at one focus (A planets distance from the sun varies during its orbit) 2. As a planet moves around its elliptical orbit, it moves faster when it's nearer the sun and slower when it is farther from the sun, sweeping out equal areas in equal times. 3. More distant planets orbit the sun at slower average speeds

the model for formation of the Moon and how this relates to differentiation within the Earth

A mars sized object struck earth At a speed and angle that blasted earths outer layers into space. according to computer simulations, this material could've collected into orbit around our planet, and accretion within this ring of the breeze could've won the moon. Evidence. The moons overall composition is quite similar to that of earths outer layers just as we should expect if it were made for material blast away from those layers. Also, the moon has a much smaller proportion of easily vaporize ingredients such as water than earth. this fact supports the hypothesis because the heat of the impact of a prize these ingredients.

Solar vs sidereal day

A solar day is the time it takes for the Earth to rotate about its axis so that the Sun appears in the same position in the sky. The sidereal day is ~4 minutes shorter than the solar day. The sidereal day is the time it takes for the Earth to complete one rotation about its axis with respect to the 'fixed' stars.

How do telescopes allow us to see fainter things and things at higher resolution? What do we mean by angular resolution?

A telescope's spatial resolution is also related to the span of its optics (lenses or mirrors). A larger baseline (effective diameter) increases spatial resolution, the ability to see detail in objects; this larger baseline can be achieved by both larger single primary mirrors and by using multiple mirrors together (even if they are spaced apart) With more light we can create a brighter image, we can then magnify the image so that it takes up more space on our retina. The big lens in the telescope (objective lens) collects much more light than your eye can from a distant object and focuses the light to a point (the focal point) inside the telescope Angular resolution:Angular resolution or spatial resolution describes the ability of any image-forming device such as an optical or radio telescope, a microscope, a camera, or an eye, to distinguish small details of an object, thereby making it a major determinant of image resolution.

What is adaptive optics

Adaptive optics essentially makes a telescope's mirrors do an opposite dance as the blurring caused by the atmosphere, canceling out the atmospheric distortions

Atom Isotope Molecule

An atom is the smallest constituent unit of ordinary matter that has the properties of a chemical element Versions of an element with different number of neutrons are called isotopes A molecule is an electrically neutral group of two or more atoms held together by chemical bonds.

Know the evidence that suggests the dinosaurs were wiped out by a large asteroid strike

And iridium which sediment layer and a 65 million-year-old crater show that a large impact occurred at the time the dinosaurs died out

Understand definitions of degrees, minutes and seconds of arc and how they define angular size.

Angular size: The angle it appears to span in your field of view. Angular distance: The angle that appears to separate pairs of objects in the sky For greater precision, we subdivide each degree into 60 arcminutes each are arcminute into 60 arcseconds.

Retrograde motion

Apparent retrograde motion is the apparent motion of a planet in a direction opposite to that of other bodies within its system, as observed from a particular vantage point.

the different kinds of force

Applied Force. Gravitational Force. Normal Force. Frictional Force. Air Resistance Force. Tension Force. Spring Force.

Why do comets have tails?

As a comet approaches the Sun, it starts to heat up. The ice transforms directly from a solid to a vapor, releasing the dust particles embedded inside. Sunlight and the stream of charged particles flowing from the Sun - the solar wind - sweeps the evaporated material and dust back in a long tail.

What is interferometry

Astronomers have developed a technology known as interferometry, which can allow multiple telescopes to work together to achieve an angular resolution equivalent to that of a much larger single telescope

direct imaging, microlensing, astrometry, transit timing

At its heart, the direct-imagingmethod resembles photography, whether via visible or infrared light. But photographing a planet isn't easy, especially when it is literally outshone by its parent star. Scientists must use an instrument known as a coronagraph to block the light from the star, revealing the dimmer light reflected by a planet in its shadow. Microlensing: A type of gravitational lensing in which the light of a star is temporarily magnified as another star passes in front of it and beans it's late. Careful study of the microlensing event can review whether the foreground star has planets. Astrometry is the branch of astronomy that involves precise measurements of the positions and movements of stars and other celestial bodies. Transit-timing variation is a method for detecting exoplanets by observing variations in the timing of a transit. This provides an extremely sensitive method capable of detecting additional planets in the system with masses potentially as small as that of Earth. In tightly packed planetary systems, the gravitational pull of the planets among themselves causes one planet to accelerate and another planet to decelerate along its orbit. The acceleration causes the orbital period of each planet to change detecting this effect by measuring the change is known as Transit Timing Variations.[1][2][3][4][5][6] "Timing variation" asks whether the transit occurs with strict periodicity or if there's a variation.

Astronomical unit

Average distance between the Earth and the Sun (150 million kilometers)

How do we get the age of the solar system?

By doing radio metric dating on meteorites

The internal structure of earth

Core: The highest density material, consisting primarily of metals such as nickel and iron, reside in the central core Mantle: Rocky material of Moderat density, mostly minerals that contain silicone, oxygen, and other elements. Crust: The lowest density rock forms a thin crust, essentially representing the worlds outer skin

What determines the length of a day/year

Day: the time it takes to complete one full rotation on its axis Year: the time the planet takes to make one full revolution around the sun

Understand how the method for finding extrasolar planets by radial velocity variations works

Doppler spectroscopy (also known as the radial-velocity method, or colloquially, the wobble method) is an indirect method for finding extrasolar planets and brown dwarfs from radial-velocity measurements via observation of Doppler shifts in the spectrum of the planet's parent star. The other method of searching for gravitational tugs do to orbiting planets is the Doppler method, which searches for a stars orbital movement around the center of mass by looking for changing Doppler shifts in its spectrum

Understand how the observations of Mars indicate that liquid water may once have existed on the surface.

Dried up river beds and other geological features show that water flowed on Mars in the distance past notice the indistinct rims a mini large craters in the relative lack of small crate it was both fax argue for ancient rainfall, which would've eroded crater rims and he raced small critters all together. Mineral evidence such as Hemetite and jarosite suggest formation in a salty environment such as a pond or lake. Curiosity found clumps of pebbles with Rounded surfaces in sedimentary layers clearly indicate formation and flowing water.

What are emission, absorption, transmission and reflection? How do these relate to color?

Emission: A light bulb emits visible light; energy of the light comes from e,E tribal potential energy supplied to the bulb Absorption: When you place your hand near an incandescent light hand absorbs some of the light, and this absorbed energy warms your hand Transmission: Some forms of matter, such as glass and air. Transmit light, which means a,knowing it to pass through Reflection: Light can bounce off matter, leading to what we call reflection(when the bouncing is all in the same general direction) The light coming from each object therefore carries an enormous amount of info ration about the o nests location, shape structure, and composition. Your brain interprets the messages that light carries, recognizing materials and objects in the process we call vision

What are the sources of the colours in the giant planet atmospheres?

For Jupiter and Saturn Light is reflected off of the ammonium hydrosulfide clouds. The cold temperatures on Uranus and Neptune allow some of their abundant methane gas to condense of the clouds. Methane gas also absorbs red light, allowing only blue light to penetrate to the level at which the methane clouds form.

Synchronous Rotation Why was it caused by tides?

From Earth we always see (nearly) the same face of the moon . This happens because the moon rotates on its axis in the same amount of time it takes to orbit Earth It's a consequence of Earths of gravity affecting the moon in much the same way the moons gravity causes tides on Earth. Synchronous rotation is the result of tidal forces that over time slow the rotation of the smaller body until it is synchronized with its period of revolution around the larger body.

properties of the surface of Titan

Has a thick atmosphere that we cannot see through with visible light. Titans reddish color comes from chemicals and its atmosphere. The atmosphere is more than 95% nitrogen, while the rest consists of Argon and methane, ethane and other hydrogen compounds. Greenhouse effect make it warmer than it would be otherwise. Lakes of liquid ethane and methane

Epicycle

He believed that this cyclical variation could be represented visually by mini orbits, or epicycles, revolving around larger circular orbits, or deferents a small circle the center of which moves around in the circumference of a larger circle: used in Ptolemaic astronomy to account for observed periodic irregularities in planetary motions.

Speed Velocity Acceleration Acceleration due to gravity

How far something will go in a certain amount of time. The speed and the direction of an object. A change in velocity The acceleration of the following object. On earth, the acceleration of gravity causes falling objects to thaw faster by 9.8 m/s with each passing second.

Understand how we now have strong evidence for three broad classes of planet

Hydrogen rich extrasolar planets vary intensity by a factor of 100, rangefar greater than the density range we observe in our solar system, but it seems reasonable to think that much of this range is attributable to increases in temperature caused by some Jovian planets being very close to their stars. Some planets appear to be Water worlds and maybe predominantly made of water, either in liquid form or as a high-pressure solid, or perhaps other hydrogen compounds. Alternatively some of these worlds might be composed of a dense rocky/metallic core and a thick layer of low density of hydrogen and helium gas. Scientist believe that extrasolar Jovian planets were indeed born with circular orbits far from there stars and that those that now have close-in orbits underwent some sort of planetary migration. Waterworld planets may be similar to Uranus and Neptune, though in some cases much smaller. These world may have been much like the ice rich planetesimals that seeded them formation of Jovian planets in our solar system. in that case, perhaps whether water worlds exist depend on when a star clears it's nebular gas, halting the epoch of planet formation.

The processes that alter Earths surface

Impact cratering: the creation of bullshit impact craters by astroids or comments striking a planet surface Volcanism: the irruption of molten rock or lava from the planets interior onto its surface Tectonics: the disruption of a planet surface by internal stresses. Erosion: the wearing down or building up of geological features by wind, water, ice, and other phenomena of planetary weather

What is the habitable zone?

In astronomy and astrobiology, the circumstellar habitable zone (CHZ), or simply the habitable zone, is the range of orbits around a star within which a planetary surface can support liquid water given sufficient atmospheric pressure.

the large moons of Jupiter and Saturn

Jupiter: io, Europa, Ganymede, and Callisto (Galilean moons) Saturn: Enceladus, Titan, Tethys, Dione, Rhea, Iapetus, Mimas

Tides and the structure of io and Europa

Jupiters mass makes its tidal force exerted on Io far larger than the tidal force the earth exerts on the moon. The result is that IO is continuously being flexed in different directions, which generates friction inside it. The flexing heats the interior. Tidal Heating generates tremendous heat on Io and calculations show that his he can explain the incredible volcanic activity Tidal heating may create a deep ocean of liquid water beneath Europa's icy crusty.

What is the Kepler satellite?

Kepler is a space observatory launched by NASA to discover Earth-size planets orbiting other stars

The different kinds of energy

Kinetic energy: Energy of motion Radiative energy: Energy carried by light Potential energy: stored energy Thermal energy: collective kinetic energy Gravitational potential energy: an objects gravitational potential energy depends on its mass and how far you can fall as a result of gravity. mass energy: Mass it's self is a form of potential energy

How planet cooling depends on size and why

Larger planets retain internal heat much longer than smaller ones and this heat drives geological activity. The total amount of heat containing a planet depends on its volume, but he can escape into space only from the planet surface. As heat escapes, more heat flows upward from the interior to replace it until the interior is no hotter than the surface. As the planet cools, geological activity ceases. The size of the planet determines planetary cooling. Extra layers act as insulation, thus taking longer for internal heat to reach the surface

Scientific method

Make observations, ask a question, suggest a hypothesis, make a prediction, perform the test: experiment or additional observation. Test supports hypothesis; make additional predictions and test them Test does not support hypothesis; revise hypothesis or make a new one

general properties of things discovered (short periods, circumbinary, in the habitable zone etc)

Many of them orbit quite close to their star despite being as large is Jupiter Many had large eccentricities Planets are common, 70% of stars harbor atleast one planet Small planets appear to outnumber large planets by a significant margin. Most of the planets are probably too hot to harbor life because of their clothes or back to their stars About 20% of stars are likely to have a planet less than twice Earth size in an orbit within the region around the start and which liquid water could potential he exist on the planet surface, the habitable zone Some orbit two star The density range for extrasolar planets is significantly wider than that for the planets in our own solar system

The Ice Line

Marked the key transition between the warm into regions of the solar system where terrestrial planets formed in the cool outer regions where Jovian planets formed. Inside the frost line, only metal and rock could condense into solid seats. Be on the frost line, the solid seats were built of ice along with metal and rock.

Understand the idea of Migration and how this helps to explain these close-in planets

Migration may be caused by waves passing through a gaseous disc. The gravity of a planet moving through a disk can create waves that propagate through the desk, causing material to bunch up as the waves pass by. This bunched up matter then exerts a gravitational pull on the planet that tends to produce its orbital energy, causing the planet to migrate inward toward it star. This helps to explain close in planets because some planets are very similar to Jovian planets however they're very close to the stars and it is possible that they went through this planetary migration before the end of the formation of the star system.

Newtons law of gravitation (Kepler variation)

Newton's law of universal gravitation states that a particle attracts every other particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. Newtons version of Kepler's third law allows us to calculate the masses of distant objects

What are constellations? The celestial sphere?

Patterns of stars; A region in the sky with well-defined borders; the familiar patterns of stars merely helps us locate these constellations The stars and constellations lie on a great sphere that surrounds earth

can be much larger than in the solar system and planets can be much closer to their parent stars than Mercury

Planet eccentricities

What is the difference between primitive and processed asteroids?

Primitive in the sense of being remnants from the time when solid material first condensed from the solar nebula. Processed in the sense that, unlike the primitive meteorites, they have been remade overtime. More specifically, processed meteor rights appear to have come from astroids that were large enough to have undergone differentiation into a core mantle crust structure.

What are the origins of the giant planet rings?

Ring systems probably owe their existence to small moons formed in the disks of gas that produce the Jovian planets billions of years ago. The rings with you today are composed of particles liberated from those moons quite recently. The numerous moonlets that formed of the disks of material orbiting the young Jovian planets are gradually been grind it down by tiny impacts.

how the method of detecting planets via transits works. What physical properties can we infer from this, and what are the biases?

Searching for slight changes in a stars brightness caused by orbiting planets. The result is a transit, in which the planet appears to move across the face of the star, causing a small, temporary dip in the system's brightness. The transit message searches for transits and eclipses by carefully monitoring a stars systems brightness over an extended period of time. The larger the planet the more dimness it will cause. Some planets that are discovered are considered candidates because even though the data showed three or more transit, the existence of this planet has not yet been confirmed by follow-up observations; as a result, theres still a small possibility that some candidates are artifacts of something besides already planning that causes the stars to dim

How is the Doppler shift relevant to spectral lines?

Spectral lines provide the reference points we use to identify and measure Doppler shifts Ex: if the hydrogen lines from the object appear at longer wavelengths, then we know they are redshifted and the object is moving away from us, and moving toward us with a blueshift.

Understand the local description of the star and how this is related to the celestial co-ordinate system.

Stars near the north celestial pole are circumpolar meaning that they remain perpetually above the horizon, circling around the north celestial pole each day Stars near the south celestial pole never rise above the horizon at all All other stars have daily circles that are partly above the horizon and partly below, which means they appear to rise in the east and set in the west.

Large fractions of _____have some kind of _____around them

Stars, planets

Stellar parallax effect

Stellar parallax is parallax on an interstellar scale: the apparent shift of position of any nearby star (or other object) against the background of distant objects.

Organization of the solar system (including masses and distances from the sun)

Sun: 333,000ME Mercury: 0.055ME, 0.39 AU Venus: 0.8ME, 0.72 AU Earth: 1.00ME, 1 AU Mars: 0.11ME, 1.52AU Asteroid belt: 2.2-3.2AU Jupiter: 318ME, 5.20AU Saturn: 95.2ME, 9.54AU Uranus: 14.5ME, 19.2AU Neptune: 17.1ME, 30.1AU Kuiper Belt: 30-50AU Pluto (dwarf planet): 0.002ME, 39.5 AU Eris: 0.0028ME, 67.7AU Oort Cloud: 5,000-100,000AU

How old is the sun? The universe?

Sun: 4.6 billion years Universe: 14 billion years

Understand the compositions of the giant planets and the interior structure

The Jovian planets are made mostly of hydrogen, helium, and hydrogen compounds, and different primarily in the relative proportions of hydrogen compounds. The cores of all four jovian planets are made of some combination of rock, metal and hydrogen compounds. Jupiter and Saturn have similar interiors, with layers extending outward of metallic hydrogen, liquid hydrogen, gaseous hydrogen, and topped with a layer of visible clouds. Unlike Jupiter and Saturn, Uranus and Neptune have cores of rock and metal, but also water, methane and ammonia. The layer surrounding the core is made of gaseous hydrogen, covered with a layer of visible clouds similar to Jupiter's and Saturn's.

Mass Momentum Angular momentum Force

The amount of matter in your body In objects momentum is the product of its mass and its velocity. Momentum use to describe objects turning in circles or going around curves The only way to change in objects momentum

What is the composition of the Earth's atmosphere and how does this regulate the greenhouse effect? What happened to the atmosphere of Venus?

The atmosphere is a mix of gases; it's overall composition is approximately 77% nitrogen and 21% oxygen, with small amounts of argon, water vapor, carbon dioxide, and other gases. Visible light passes through the atmosphere. Some visible light is reflected by clouds, haze, and the surface. The surface absorbs visible light in the mid sternal radiation and infrared. Greenhouse gases absorb and emit infrared radiation, there by heating the lower atmosphere. The greenhouse effect occurs when the atmosphere temporarily trap some of this infrared light, slowing its return to space. Venus is the carbon dioxide atmosphere created extremely strong greenhouse effect that makes Venus very hot. Venus must have somehow lost its outgassed water. Without oceans, carbon dioxide cannot dissolve or become locked away in carbonate rocks.

Phases of venus

The different variations of lighting seen on the planets surface, similar to lunar phases. This was evidence that supported the heliocentric model because if the earth were the center of the universe Venus would only go through four phases; however, it was observed that Venus went through eight phases, proving that the sun was the center of the universe.

Light year

The distance light travels in a year, used to express astronomical distances (9.5 trillion kilometers)

Escape velocity

The escape velocity from earth's surface is about 40,000 km/h or 11 km/s; this is the minimum velocity required to escape earths gravity for a spacecraft that starts near the surface.

What is the evidence for water in Enceladus

The fountains of water vapor and ice crystals must have some sub service source, and careful measurements of the way on Cletus wobbles on its axis as it orbits Saturn have lead scientist to suspect that I included as a global, sub surface ocean of liquid water.

Know the basic physical characteristics of the planets (rocky/gas) and their atmospheres (thin/thick)

The giant outer planets Jupiter, Saturn, Uranus, and Neptune have extremely thick atmospheres of hydrogen, helium, methane, and ammonia. Gaseous Mercury: rocky,thin Venus: rocky, thick Earth:rocky, thin Mars: rocky, thin Pluto: rocky, thin

Occam's razor

The idea that scientists should prefer the simpler of two models that agree equally well with observations

Laws of conservation

The law of conservation of angular momentum tells us that total angular momentum can never change. an individual object can change is angular momentum only by transferring some angular momentum to or from another object. The law of conservation of energy tells us that, like momentum and angular momentum, energy cannot appear out of nowhere or disappear into nothingness. Objects can gain or lose energy only by exchanging energy with other objects.

The phases of the moon and the physical reasons for them

The lunar phase or phase of the moon is the shape of the illuminated portion of the Moon as seen by an observer Half the moon is always illuminated by the sun, but the amount of this illuminated half that we see from Earth depends on the Moon's position in its orbit.

What is an eclipse and why is it rare

The moon and earth both cast shadows in sunlight, and these shadows can create eclipses when the sun, earth, and moon fall into a straight line. Eclipses come in two basic types: Lunar eclipse: occurs when Earth lie directly between the sun and the moon, so earth's shadow falls on the moon Solar eclipse: occurs when the moon lies directly between the sun and earth, so the moons shadows falls on earth We see an eclipse only when a full or new moon occurs near one of the points where the moons orbits crosses the ecliptic plane

What is the nebular theory and what observations support it?

The nebular theory holds that our solar system form from the gravitational collapse of a great cloud of gas 1. All the planets orbit the Sun in the same direction. Most of their moons also orbit in that direction, and the planets (and the Sun) rotate in the same direction. This would be expected if they all formed from a disk of debris around the proto-Sun. 2. The planets also have the right characteristics to have formed from a disk of mainly hydrogen around a young, hot Sun. Those planets near the Sun have very little hydrogen in them as the disk would have been too hot for it to condense when they formed. Planets further out are mostly hydrogen, (since that was what was mostly in the disk), and are much more massive because there was so much more material they could be made from. Finally in this model the Sun is mostly composed of hydrogen. This can also be tested. Observations of the Sun agree incredibly well with what would be expected of a giant ball of mostly hydrogen generating heat by nuclear fusion in the core. The composition can also be measured using helioseismology (the study of 'Sunquakes') and agrees with the theory.

What is the ecliptic and the Milky Way?

The path the sun follows as it appears to circle around the celestial sphere once each year. It cross the celestial equator at a 23% angle, because of Earth axis tilt. Our view in all directions into the disk of our galaxy. The band of light we call the Milky Way circles all the way around the celestial sphere, passing through more than a dozen constellations.

What are the sources of internal heat for a planet?

The process of differentiation converted additional gravitational potential energy into thermal energy is denser materials sector the corner. The rock and metal that built the terrestrial worlds contain radioactive isotopes of elements. As these radioactive materials decay they release heat directly into the planetary interiors in essence converting some of the mass energy of the radioactive nuclei to thermal energy.

What is the rotation of these giant planets?

The rotation period we measure in this way is 9 hours 56 minutes, which gives Jupiter the shortest "day" of any planet. In the same way, we can measure that the underlying rotation period of Saturn is 10 hours 40 minutes. Uranus and Neptune have slightly longer rotation periods of about 17 hours, also determined from the rotation of their magnetic fields.

the solar system inventory: know the planets and their properties. Know where the asteroids and comets reside

The sun; gaseous 99.8% of the solar system mass Mercury; smallest planet, desolate and cratered, extreme temperatures, large iron core Venus; routes backwards, nearly identical in size to earth, hidden by clouds, extreme greenhouse effect Earth; only life, oxygen, ozone, water, first planet with a moon Mars; half earths size, ancient volcanoes, great canyon, once had warm and wet periods, Asteroid belt Jupiter; largest planet, mass 300 times more than earth, Great Red Spot, hydrogen and helium, no solid surface, dozens of moons and faint rings, Saturn; orbit twice as far as Jupiter, second largest, 4 large rings made of tiny particles, numerous moons, river beds shaped by Methane and ethane rather than water Uranus; twice as far as Saturn, methane gives Uranus its pale blue green color, no solid surface, rings, tipped on its side, most extreme seasonal changes Neptune; slightly smaller than Uranus, rings and many moons, triton with geysers of nitrogen gas that orbits backwards, Kuiper belt Pluto; dwarf planet, Kuiper belt, extremely cold and dimly lit, Charon Eris; dwarf planet, larger than Pluto, Kuiper belt Oort Cloud (comets)

Understand the basic sequence of planet formation from small bodies to large, and how this helps to explain rocky planets and gas giants

The terrestrial planets started out as small solid seed of metal and rock in the inner solar system. Then through collisions and combination and electrostatic forces, they began to attract each other through gravity, accelerating their growth into boulders large enough to count as planetesimals. This gave them more surface area to make contact with other planetesimals and more gravity to attract them. But once they reached larger sizes, further growth became difficult. The Jovian planets began as large icy planetesimals which then captured hydrogen and helium gas from the solar nebula. This added gas made their gravity even stronger allowing them to capture even more gas.

What causes the seasons

The tilt of earths axis causes sunlight to fall differently on Earth at different times of year

How does temperature relate to thermal energy?

Thermal energy measures the total kinetic energy of all the randomly moving particles in a substance, while temperature measures the average kinetic energy of the particles. Thermal energy depends on temperature, because a higher average kinetic energy for the particles in a substance means a higher total energy.

The photoelectric effect

Under the right circumstances light can be used to push electrons, freeing them from the surface of a solid. The photoelectric effect refers to the emission, or ejection, of electrons from the surface of, generally, a metal in response to incident light. ... That is, the average energy carried by an ejected (photoelectric) electron should increase with the intensity of the incident light.

the names for the different parts of the electromagnetic spectrum and what distinguishes one from another (don't need the numbers, just the reason)

Visible light has wavelengths ranging from 400nm at the blue or violet end of the rainbow to about 700nm at the red end. Light with wavelength somewhat longer than red light is called infrared because it lies beyond the red end of the rainbow Radio waves are the longest wavelength light The region near the border between infrared and radio waves where wavelengths range for micrometers to centimeters is often called microwaves Light with wavelength somewhat shorter than blue light is called ultraviolet because it lies on the blue end of the rainbow But with even shorter wavelengths is called x-rays. The shortest wavelength light is called gamma rays

Relative size scales of the solar system

Voyage model: Sun is grapefruit Jupiter is a marble Earth is the ballpoint of a pen (orbiting the sun at a distance of 15m) Moon is 4 centimeters from Earth

What sort of information can we get with this method and what are the selection effects/biases that result from using this method.

We can learn the planets approximate mass, we can learn the center of mass for the star system, the orbital period and therefore surface temperature. RV method is biased towards finding the most massive exoplanets. Also best suited for identifying planets that orbit relatively close to their star, because being closer means a stronger gravitational tug and hits a greater velocity for the star as it orbits the system center of mass. Shorter Orbits also allow easier confirmation of the planets existence, because it is easier to record multiple repeats of the Doppler curve.

Understand how the cooling of Mars ultimately resulted in the loss of the Atmosphere

When mars had a warmer core which generated stronger magnetic field the warmer interior caused extensive volcanism and out gassing. The stronger magnetosphere protected atmosphere from solar wind in this atmosphere was created by the outgassing and volcanism. However, the lack of core convection meant no global magnetic field. The weaker magnetosphere has allowed solar wind to strip away much of the atmosphere.

What is the definition of a planet?

a celestial body distinguished from the fixed stars by having an apparent motion of its own (including the moon and sun), especially with reference to its supposed influence on people and events. It is in orbit around the Sun. It has sufficient mass to assume hydrostatic equilibrium (a nearly round shape). It has "cleared the neighborhood" around its orbit.

What is an ellipse? How is it described by the parameter eccentricity?

a regular oval shape, traced by a point moving in a plane so that the sum of its distances from two other points (the foci) is constant, or resulting when a cone is cut by an oblique plane that does not intersect the base By altering the distance between the two foci while keeping the length of string the same, you can draw ellipses of carrying eccentricity, a quantity that describes how much an ellipse is stretch out compared to a perfect circle.

Greek geocentric model?

astronomy, the geocentric model (also known as geocentrism, or the Ptolemaic system) is a superseded description of the universe with Earth at the center. Under the geocentric model, the Sun, Moon, stars, and planets all orbited Earth

What is the spectrum of star/planet and how can we use it to tell the chemical composition of the atmosphere? How does it show the temperature of a planet?

the spectra that we see coming from stars often contain what look like dark lines at particular colors, which means there is much less light coming from the star at that color than at the nearby colors. This usually means that the star's atmosphere contains certain types of molecules which absorb light of that color, so we don't see as much of it coming from the star. Astronomers can use the information from these "spectral lines" to figure out what a star is made of. Because the randomly bouncing photons interact so many times with those Atoms or molecules, they end up with energy levels that match the kinetic energies of the objects' atoms or molecules which means the photon energies depends only on objects temperature, regardless of what object is made of.