Astronomy Final
What are the 4 criteria that define a planet?
1) Have enough mass/gravity to be round. 2) Orbit the Sun. 3) Not be a moon/satellite. 4) Clear out orbital neighborhood. (Or, be the dominant source of gravity in the orbital zone)
What best describes the rings around the giant planets? A.Solid disks of material. B.A swarm of orbiting rocks and dust. C.Rocks trapped by the planets' magnetic fields. D.Debris clouds from ancient asteroid impacts.
B.A swarm of orbiting rocks and dust.
What is the name of the process by which planetesimals merge together to build up to the size of protoplanets? A.Accumulation B.Accretion C.Gravitational acquisition D.Orbital condensation
B.Accretion
If we observe a star 108 light-years away, which of the following must be true about that star? A. The star is 108 times larger than the Sun. B. The star is 108 years old. C. The light we see left the star 108 years ago. D. The star is 108 times smaller than the Sun
C. The light we see left the star 108 years ago.
On a clear night you can observe the "Milky Way" in the night sky. What is it that you're observing? A. A nearby star cluster. B.Stars in the stellar neighborhood. C.The flat disk of our galaxy. D.A nearby gas cloud.
C.The flat disk of our galaxy.
If we observe a star 50 light-years away, which of the following must be true about that star? A.The star is 50 times larger than the Sun. B.The star is 50 million years old. C.The light we see left the star 50 years ago. D.The light we see left the star 50 minutes ago.
C.The light we see left the star 50 years ago.
How is our Solar System like the Milky Way? A.They are mostly empty space. B.Hydrogen is the most abundant element. C.Objects (planets/stars) revolve in a flat plane. D.The most massive object is in the center. E.All of the above.
E.All of the above.
What percentage of the Sun's composition is made up of the following elements? Hydrogen: Helium: Other:
Hydrogen: 78% Helium:20% Other:2%
In Solar Mass units, in what mass range do we expect to find most stars?
0.08 Msun < Mstar < 150 Msun
Planet Eccentricity Mercury 0.206 Venus 0.007 Earth 0.017 Mars 0.094 Jupiter 0.048 Saturn 0.054 Using the above table, which planet has the most elliptical orbit? Using the above table, which planet has the most circular orbit?
1. Mercury 2. Venus
What are the four stages of terrestrial planet formation, in order? 1st stage 2nd stage 3rd stage 4th stage
1st stage Differentiation 2nd stage Bombardment 3rd stage Cooling 4th stage Surface Evolution
What are the four stages of terrestrial planet formation in order? (No need to define them, just the names of the stages).
1st stage: Differentiation 2nd stage: Bombardment 3rd stage: Cooling 4th stage: Surface Evolution
Convert the following numbers into scientific notation: 8,400 0.0056 55,000,000,000 0.008 x 10^5
8,400 = 8.4 x 10^3 0.0056 = 5.6 x 10^-3 55,000,000,000 = 5.5 x 10^10 0.008 x 10^5 = 8.0 x 10^2
What are the two most important factors that determine the surface evolution of a terrestrial planet? (CIRCLE TWO) A. The planet's distance from the Sun. B. The presence of a magnetic field. C. The rotation rate of the planet. D. The size of the planet. E. The number of volcanoes on the planet's surface.
A. The planet's distance from the Sun. D. The size of the planet.
Some of the most distant objects we observe in the Universe are quasars, which emit very bright X-ray jets. What is a quasar? A. A supermassive black hole consuming material. B.An especially bright supernova. C.Two galaxies merging. D.A white dwarf imploding .
A. A supermassive black hole consuming material.
Comets are icy rocks with highly eccentric orbits around the Sun. From Kepler's 2nd law (equal areas in equal times), what can we infer about comet orbits if we observe them to spend months in the inner solar system? A. Comets must spend years in the outer solar system. B. Comets must be small to move fast through the inner solar system. C. Comets must have a constant orbital speed. D. Comets must have an orbit with a semi-major axis less than 1 AU.
A. Comets must spend years in the outer solar system.
What two factors lead to Earth's magnetic field? (Circle two)' A. Earth's rotation rate. B. Tidal forces from the Moon. C. Convection in the liquid portion of Earth's core. D. Charged particles in the Earth's atmosphere. E. Convection in the Earth's mantle.
A. Earth's rotation rate. C. Convection in the liquid portion of Earth's core.
If a star emits most of its energy in the infrared region of the light spectrum, what color will it appear to our eyes? A. Red B. Yellow C. Green D. Blue
A. Red
What is the most important factor in determining if a terrestrial planet has liquid surface water? A.A planet's distance from the Sun. B.The presence of a dipole magnetic field. C.The rotation rate of a planet. D.The size of a planet.
A.A planet's distance from the Sun.
To find the distance to stars on the other side of the Milky Waywe use standard candles(objects with a known luminosity)and the inverse-square law. What objects do we use as standard candles? A.Cepheid variables B.White dwarfs C.Gamma-ray bursts D.Brown dwarfs
A.Cepheid variables
What is the most likely reason that Jupiter's atmosphere contains several storms (like the Great Red Spot)? A.Friction and turbulence between its cloud bands. B.Its strong magnetic field. C.Tidal forces from its many moons. D.A large amount of volcanic outgassing.
A.Friction and turbulence between its cloud bands.
What element is the fuel for fusion reactions in the Sun's core? A.Hydrogen B.Helium C.Carbon D.Oxygen E.Nitrogen
A.Hydrogen
Why is the Earth's core composed of mostly metals (like iron and nickel)? A.Iron and nickel are the densest elements. B.Iron and nickel don't melt like other elements. C.Iron and nickel are less dense than other elements. D.Iron and nickel cool faster than other elements.
A.Iron and nickel are the densest elements.
On Mercury, scarps (cliffs) cut across the surface and interrupt crater patterns. What is the origin of scarps? A.Mercury cooling and shrinking. B.Cracks formed by asteroid impacts. C.Tidal forces from the Sun. D.Mercury's strong magnetic field.
A.Mercury cooling and shrinking.
The elliptical orbits of the planets around the Sun are best explained by which of Newton's laws? A.Newton's 1st Law. B.Newton's 2nd Law. C.Newton's 3rd Law. D.Newton's 4th Law.
A.Newton's 1st Law.
What is the main reason that Earth is not covered in craters (remnants of the Bombardment phase of planet formation)? A.Surface evolution. B.Planet cooling. C.Differentiation. D.Convection.
A.Surface evolution.
What bestdescribes the Big Bang Theory? A.The Universe was once in a hot and dense state. B.The Universe is one small part of the Multiverse. C.The Universe formed in a gigantic explosion. D.The implosion of another Universe created our Universe.
A.The Universe was once in a hot and dense state.
How was the geocentric model of the Solar System modified to explain the apparent retrograde motion of planets? A.The addition of epicycles. B.The outer planets have the opposite rotation direction compared to the inner planets. C.The geocentric model didn't need to be modified. D.The gravity of Jupiter occasionally makes some planets reverse orbital direction.
A.The addition of epicycles.
What is the definition of an Astronomical Unit (AU)? A.The distance between the Earth and the Sun. B.The diameter of our Solar System. C.The distance between the Sun and the center of the Milky Way. D.The light travel time from the Earth to the Sun.
A.The distance between the Earth and the Sun.
Which of the following is true about the force of gravity? A.The gravitational force between two objects becomes stronger the closer the objects are to each other. B.The surface gravity of the Moon is greater than the surface gravity of Earth. C.The Earth and Venus experience the same gravitational force from the Sun. D.The gravitational force between two objects becomes weaker as the objects move closer to each other.
A.The gravitational force between two objects becomes stronger the closer the objects are to each other.
Jupiter's moon Io has volcanic activity because we see fresh lava flows and the surface is covered in sulfur. Because Io is roughly the size of Earth's moon, and is about the same age, we would expect Io to have a cold interior and no volcanic activity. How has Io remained hot enough in its interior to have volcanic activity? A.Tidal forces from Jupiter releases heat in Io's interior. B.Io has nuclear fusion in its core. C.Io is made up of mostly radioactive material that keeps the interior warm. D.Io's interior is heated by Jupiter's strong magnetic field.
A.Tidal forces from Jupiter releases heat in Io's interior.
At the center of the Milky Way is a supermassive black hole that is about ~3x106times the mass of the Sun. How do we measure the mass of the supermassive black hole? A.Using the orbits of stars around the black hole. B. How bright the black hole is in ultraviolet light. C. Aurora in the magnetic field of the black hole. D. We've observed the black hole consume millions of stars.
A.Using the orbits of stars around the black hole.
What two factors cause colored bands to form in Jupiter's atmosphere? A.convection B.magnetic fields C.contraction D.planet rotation (the Coriolis effect) E.turbulence
A.convection D.planet rotation (the Coriolis effect)
Which of the following orbits is closest to a circle? Planet Eccentricity Mercury 0.206 Venus 0.007 Earth 0.017 Mars 0.094
Venus 0.007
magine you discover a rock composed of 1/4 (25%) Uranium parent atoms and 3/4 (75%) Uranium daughter atoms. How many half-lives would you determine the rock has undergone? A.1 B.2 C.3 D.4
B. 2
Beyond the orbit of Neptune is the Oort cloud. What best describes the Oort cloud? A. A large spherical cloud of molecules. B. A large spherical shell of small icy rocks. C. A large spherical shell of charged particles. D. A large spherical cloud of only S-type asteroids.
B. A large spherical shell of small icy rocks.
What observation tells us about the composition of the Sun's outer layers? A. Emission spectra from the solar wind. B. Absorption spectra from the photosphere. C. Sunspots in the photosphere. D. Granules in the photosphere.
B. Absorption spectra from the photosphere.
Imagine that we observe a gas cloud out in the galaxy and we see emission lines (emission spectra) from the cloud. What is causing the cloud to emit light? A. It's emitting infrared radiation (heat). B. It emits light as electrons spontaneous change energy levels. C. It's reflecting light from nearby stars. D. It emits light when atoms inside undergo radioactive decay.
B. It emits light as electrons spontaneous change energy levels.
The Moon is in a synchronous orbit about the Earth, which means it rotates once for every one revolution around the Earth. This is a good example of what? A. Orbital eccentricity. B. Orbital resonance. C. Tidal action. D. The Coriolis effect.
B. Orbital resonance.
How have scientists learned about the interior structure of the Earth and the Moon?A. Topographical mapping B. Seismology C. Volcanology D. Radar modeling
B. Seismology
The Sagittarius Dwarf Spheroidal galaxy is a Milky Way satellite that is being consumed by the Milky Way galaxy. This is a good example of what? A.The gravitational pull of the Milky Way's dark matter halo. B.Accretion of a dwarf galaxy onto a larger galaxy. C.Galaxies merging to form a galaxy cluster. D.Two dwarf galaxies merging to form an irregular galaxy.
B.Accretion of a dwarf galaxy onto a larger galaxy.
What best describes the source of Earth's dipole magnetic field? A.Convection in the mantle. B.Convection and rotation in the liquid metal core. C.Tidal forces from the Moon. D.The rotating solid metal core.
B.Convection and rotation in the liquid metal core.
What observation provides evidence that nuclear fusion is occurring inside the Sun's core? A.Observations of gamma rays from the Sun. B.Detection of neutrinos from the Sun. C.Absorption spectra of the Sun's photosphere. D.Calculations from Helioseismology.
B.Detection of neutrinos from the Sun.
Our Solar System is about 26,000 light-years from the center of the Milky Way. From our vantage point on Earth, why is it difficult to observe the center of the galaxy? A.The Earth rotates too rapidly. B.Interstellar gas and dust absorbs light and obstructs our view. C.Light from the center of the galaxy does not shine toward us. D.The center of the galaxy is too far away to be observed.
B.Interstellar gas and dust absorbs light and obstructs our view.
Unlike Earth, the orbit of Mars has a more significant impact on its climate. Why is this? A.Mars' orbital period around the Sun is longer than Earth's. B.Mars' orbit has a higher eccentricity than Earth's. C.Tides from Mars' moons are weaker. D.Mars' orbit has a lower eccentricity than Earth's.
B.Mars' orbit has a higher eccentricity than Earth's.
Why is the Earth's core composed of mostly metals (like iron and nickel)? A.Metals don't melt like other elements. B.Metals are the densest elements. C.Metals are less dense than other elements. D.Metals cool faster than other elements.
B.Metals are the densest elements.
The Big Bang (when everything in the Universe was together) was about 13.8 billion years ago. What are the two main pieces of supporting evidence for the Big Bang? (circle two) A.The masses of supermassive black holes. B.The Cosmic Microwave Background. C.The abundances of hydrogen and heliumthroughout the Universe. D.The number of globular clusters in the Milky Way. E.The amount of dark matter in the Universe.
B.The Cosmic Microwave Background. C.The abundances of hydrogen and heliumthroughout the Universe.
How have scientists determined that the Earth is about 4.6 billion years old? A.The presence of old impact craters. B.The abundances of radioactive material in rocks. C.The temperature of Earth's core. D.The amount of oxygen in the atmosphere.
B.The abundances of radioactive material in rocks.
In the heliocentric model of the Solar System, how is the apparent retrograde motion of planets explained? A.The daily rotation of the Earth. B.The motion of the Earth around the Sun. C.The tilt of the Earth's rotation axis. D.Epicycles.
B.The motion of the Earth around the Sun.
What do we observe during the apparent retrograde motion of a planet? A.The planet fades from view. B.The planet temporarily reverses its eastward motion in the sky. C.The planet rises in the West instead of the East. D.The planet moves below the horizon for the remainder of the year.
B.The planet temporarily reverses its eastward motion in the sky.
What is the main evidence for dark matter in the Milky Way and other galaxies? A.The presence of a supermassive black hole at the center. B.The rotation speed of stars in the galactic disk. C.Low energy radio signals from dark matter clouds. D.X-ray bursts when dark matter is consumed by a black hole.
B.The rotation speed of stars in the galactic disk.
What is the cause of Earth's seasons? A.The eccentricity of Earth's orbit. B.The tilt of Earth's rotation axis. C.The speed of Earth's rotation. D.The orbital speed of Earth around the Sun.
B.The tilt of Earth's rotation axis.
We can observe other planets in the Solar System because A.they produce their own visible light. B.they reflect some of the sunlight that reaches them. C.we use telescopes to shine lights on them. D.we observe them when the move closer to the Sun than Earth.
B.they reflect some of the sunlight that reaches them.
What two things balance each other to keep the Sun in gravitational equilibrium? (choose two) A. The energy from the Sun's magnetic field. B. The centrifugal force from the Sun's rotation. C. The gravity of the Sun. D. The convection of the Sun's outer layers. E. Energy from fusion in the Sun's core.
C. The gravity of the Sun. E. Energy from fusion in the Sun's core.
The oldeststars in the Milky Way galaxy are found in what region? A.Thin disk B.Thick disk C.Halo D.Central Bulge
C. Halo
If we happened to observe a star that emits most of its light in the X-ray region of the light spectrum, what would likely be true about its mass? A. Lower mass than the Sun. B. Similar in mass to the Sun. C. Higher mass than the Sun.
C. Higher mass than the Sun.
What is the most likely reason there is an asteroid belt between Mars and Jupiter? A. An asteroid collision with Mars ejected rocks into space. B. Asteroids were captured by Jupiter's gravity. C. Jupiter's gravity prevented a planet from forming. D. Jupiter's magnetic field captured magnetic rocks.
C. Jupiter's gravity prevented a planet from forming.
Asteroids in the asteroid belt have three composition types (C, S, and M-types). What best describes the M-type asteroids? A. M-types are only composed of molecular hydrogen. B. M-types are molten (high-temperature) asteroids. C. M-types are composed of metals. D. M-types come from the orbit of Mars.
C. M-types are composed of metals.
What is the name of the technique that uses triangulation (or geometry) to calculate the distance to nearby stars? A.Doppler method B.Radial velocity technique C.Parallax D.Trajectory mapping
C. Parallax
We theorize that all galaxies form from the gravitational contraction of a gas cloud (like stars, but on a larger scale). If galaxies form in this way, what must be true about galaxies? A.Galaxies are always as large, or larger, than the Milky Way. B.Most galaxies must be spirals. C.Small galaxies (dwarf galaxies) are more numerous. D.Galaxies will never cluster together.
C. Small galaxies (dwarf galaxies) are more numerous.
What causes sunspots in the Sun's photosphere? A. Asteroids impacting the Sun's surface. B. Interaction of the photosphere with the solar wind. C. The Sun's magnetic field. D. Turbulence in the Sun's atmosphere.
C. The Sun's magnetic field.
The Earth's climate remains stable over millions of years because of what two processes? (CIRCLE TWO) A. The Coriolis effect. B. The water cycle. C. The greenhouse effect. D. Plate tectonics.E. The tides. F. Th e CO2 cycle.
C. The greenhouse effect. F. Th e CO2 cycle.
The Sun emits most of its energy in what wavelength region of the light spectrum? A. Gamma-rays B. Ultraviolet C. Visible D. Infrared E. Radio
C. Visible
Jupiter rotates once every 10 hours, more than twice as fast as the Earth. Along with rapid rotation, what other property of Jupiter leads to it having a very strong magnetic field (20,000x Earth)? A.A high pressure atmosphere. B.Friction between its cloud bands. C.A thick, convecting, metallic hydrogen layer. D.Tidal forces from its many moons.
C.A thick, convecting, metallic hydrogen layer.
The ecliptic is the path the Sun takes along the celestial sphere. Why do the planets also travel along the ecliptic in the sky? A.The tilt of the Earth's rotation axis. B.They only appear to travel along the ecliptic because they are so far away. C.Because all planets in the Solar System orbit the Sun in a flat plane. D.They appear on the ecliptic because of their epicycles.
C.Because all planets in the Solar System orbit the Sun in a flat plane.
Why does Venus appear to be yellow in color? A.Its atmosphere emits heat as yellow light. B.Carbon dioxide in its atmosphere absorbs yellow wavelengths of light. C.Carbon dioxide in its atmosphere reflects yellow wavelengths of light. D.Oxygen in its atmosphere absorbs yellow wavelengths of light.
C.Carbon dioxide in its atmosphere reflects yellow wavelengths of light.
What is causing the Universe to acceleratein its expansion? A.Supernova explosions B.Dark matter C.Dark energy D.Angular momentum
C.Dark energy
What makes dark matter different from ordinary matter? A.Dark matter can only exist inside black holes. B.Dark matter doesn't interact with gravity. C.Dark matter doesn't interact with light. D.Dark matter is only found in elliptical galaxies.
C.Dark matter doesn't interact with light.
Which four planets in the Solar System are terrestrial planets? A.Mars, Earth, Mercury, Jupiter B.Mercury, Saturn, Venus, Mars C.Earth, Venus, Mercury, Mars D.Neptune, Mercury, Venus, Earth
C.Earth, Venus, Mercury, Mars
Evidence of dry river beds on the Martian surface suggest that it once had liquid surface water. Presence of surface water in the past suggests that Mars was once warmer; what else does it suggest? A.Mars once had a climate identical to Earth's current climate. B.Mars once had an oxygen atmosphere. C.Mars once had a thicker atmosphere. D.Mars was once a more massive planet.
C.Mars once had a thicker atmosphere.
Mars has many ancient dry river beds on its surface. Craters interrupt and erase some of the dry river bed patterns. What does this imply about Mars? A.The Martian atmosphere has always been as thin as we see it today. B.Mars had oceans covering most of its surface at one time. C.Martian rivers dried up before the bombardment stage of Mars' formation. D.Martian craters must be volcanoes.
C.Martian rivers dried up before the bombardment stage of Mars' formation.
Which of the following correctly lists objects in order from smallest to largest? A.Milky Way, Solar System, Sun, Earth, Moon B.Sun, Solar System, Milky Way, Moon, Earth C.Moon, Earth, Sun, Solar System, Milky Way D.Moon, Milky Way, Sun, Earth, Solar System
C.Moon, Earth, Sun, Solar System, Milky Way
How have scientists learned about the structure of Earth's interior? A.Drilling B.Terraforming C.Seismology D.Volcanic activity
C.Seismology
What do we use as a standard candleto find distances to the most distant galaxiesin the Universe? A.Nova (explosions on white dwarfs) B.X-ray bursts (explosions on neutron stars) C.Supernovae D.Merging black holes
C.Supernovae
What is the name of the theory that attempts to explain the origin of the Solar System? A.The Planetary Nebula theory. B.The Helioformation theory. C.The Solar Nebula theory. D.The Gravitational Contraction theory.
C.The Solar Nebula theory.
In the geocentric model of the Solar System, the apparent retrograde motion of Mars is explained by giving Mars a small orbit of its own, called an "epicycle". In the heliocentric model of the Solar System, Mars' apparent retrograde motion can be explained by what? A.The eccentricity of Mars' orbit. B.The daily rotation of the Earth. C.The motion of the Earth around the Sun. D.The tilt of the Earth's rotation axis.
C.The motion of the Earth around the Sun.
Using Kepler's 3rd law of planetary motion, if we measure the semi-major axis of a planet's orbit around the Sun, what can we immediately determine about its orbit? A.The orbital speed of the planet. B.The semi-minor axis of the planet's orbit. C.The orbital period of the planet's orbit. D.The eccentricity of the planet's orbit.
C.The orbital period of the planet's orbit.
What observation did Galileo make with the first telescope that provided evidence in support of the heliocentric model of the Solar System? A.The retrograde motion of Mars. B.The moons of Jupiter. C.The phases of Venus. D.Mercury orbiting the Sun.
C.The phases of Venus.
Using Kepler's 3rd Law, if we measure the orbital period of a planet orbiting the Sun, what else can we determine about its orbit? A.The radius of the planet. B.The mass of the planet. C.The semi-major axis of the planet's orbit. D.The orbital speed of the planet.
C.The semi-major axis of the planet's orbit.
What is the cause of Earth's seasons? A.The eccentricity of Earth's orbit. B.The CO2 cycle. C.The tilt of the Earth's rotation axis. D.The combined tidal forces of the Sun and the Moon.
C.The tilt of the Earth's rotation axis.
What best explains why elliptical galaxies appear red? A.They are all moving away from the Milky Way at high speeds. B.Only low-mass red stars ever form in elliptical galaxies. C.They don't have enough gas to have new star formation. D.Their blue stars are too dim to be resolved by telescopes.
C.They don't have enough gas to have new star formation.
What is true of the first generation of stars to form in the Universe? A.They are observed in great numbers in theMilky Way's globular clusters. B.They didn't have hydrogen fusion in their cores. C.They were very massive stars (greater than 100x the mass of the Sun). D.They were only made of dark matter.
C.They were very massive stars (greater than 100x the mass of the Sun)
As the gas cloud that formed our solar system contracted under its own gravity it began to flatten and spin faster. What is the main reason that the cloud flattened and began spinning faster?
Conservation of angular momentum.
Meteor showers occur when large groups of meteoroids fall through Earth's atmosphere. What best describes the origin of meteor showers? A. Material ejected from the Sun during a solar flare. B. Pieces left over from the Moon's formation. C. Pieces of disintegrated C-type asteroids. D. The debris trails left by comets that intersect Earth's orbital path.
D. The debris trails left by comets that intersect Earth's orbital path.
What pattern do we see with the planets that is also seen with stars? A. The highest mass ones are bluest. B. They have nuclear fusion in their cores. C. They are primarily composed of helium. D. The lower mass objects are more numerous. E. All of the above.
D. The lower mass objects are more numerous.
In the Milky Way galaxy, which of the following objects would we expect to be the most numerous? A.Red stars B.Yellow stars (like the Sun) C.Blue stars D.Brown dwarfs
D.Brown dwarfs
What best describes the cause of aurora in Earth's atmosphere at high latitudes? A.The Earth losing heat through infrared radiation. B.Tidal forces from the Moon. C.Gamma rays diffusing through Earth's atmosphere. D.Charged particles interacting with the Earth's magnetic field.
D.Charged particles interacting with the Earth's magnetic field.
What is the source of Earth's oxygen (O2 and O3) atmosphere? A.Volcanic outgassing B.The CO2 cycle C.The water cycle D.Life
D.Life
What is the best evidence for the Large Impact Hypothesis of the Moon's formation? A.The large size of the Moon relative to other moons in the Solar System. B.The tilt of the Earth's rotation axis. C.The lack of an atmosphere on the Moon. D.Moon rocks with a composition close to that of the Earth's crust
D.Moon rocks with a composition close to that of the Earth's crust
Mars has two moons, Phobos and Deimos. What makes these moons unique among the moons of the terrestrial planets? A.Phobos and Deimos have atmospheres. B.Phobos and Deimos are the result of a large impact on Mars. C.Phobos and Deimos have synchronous orbits around Mars. D.Phobos and Deimos are captured asteroids.
D.Phobos and Deimos are captured asteroids.
What does Kepler's 2nd Law of planetary motion say about planetary orbits? A.All planets orbit the Sun in ellipses. B.The orbital period of a planet is related to its semi-major axis. C.The Sun sits at a focus point in all elliptical orbits. D.Planetary orbits sweep out equal areas in equal times.
D.Planetary orbits sweep out equal areas in equal times.
What is the theory that says the Milky Way formed from a large proto-galactic gas cloud? A.The Solar Nebula Theory B.The Galactic Cloud Theorem C.The Galactic Nebula Theory D.The Monolithic Collapse Theory
D.The Monolithic Collapse Theory
Hubble's Law is derived from the fact that we observe more distantgalaxies moving away from us at a faster speed. What is the reason for this relationship between galaxy distance and speed? A.Dark matter in galaxies pushes them apart. B.Supermassive black holes in galaxiesare repelledfrom one another. C.Supernova explosions push galaxies apart. D.The Universe is expanding.
D.The Universe is expanding.
We predict the early Universe would be hot and dense, and shine like a star at T=3000 K. However, when we add up all the light from the Cosmic Microwave Background it looks like a star shining at T= 3 K. What causes this differencein temperature? A.Light from the Big Bang has been mostly absorbed by clouds. B.Light from stars has mixed with light from the Big Bang. C.Light from the Big Bang interacts with dark matter. D.The Universe's expansion has stretched the light from the Big Bang to longer wavelengths.
D.The Universe's expansion has stretched the light from the Big Bang to longer wavelengths.
Which of the following observations provides evidence for a heliocentric model of the Solar System? A.The phases of the Moon. B.The apparent retrograde motion of Mars. C.The rotation of stars around the celestial poles. D.The phases of Venus.
D.The phases of Venus.
How have scientists learned that the Earth is likely 4.6 billion years old? A.The temperature of the Earth's core. B.The eccentricity of the Moon's orbit. C.The size of craters on Earth's surface. D.The radioactive dating of rocks.
D.The radioactive dating of rocks.
What clues do we have that suggest the Solar System formed from a gravitationally contracting gas cloud? A. The consistent ages of the planets, asteroids, and the Sun. B. The common rotation direction of all the planets around the Sun. C. The composition of planets depending on their distance from the Sun. D. The planets all orbit in a plane around the Sun. E. All of the above.
E. All of the above.
Which of the following orbits is the most elliptical? Object Eccentricity Jupiter 0.048 Saturn 0.054 Uranus 0.048 Neptune 0.007
Saturn 0.054
What is the definition of an astronomical unit (AU)? (Not the number, just how it is defined/where it comes from.)
The distance between the Earth and the Sun.