This is Form A (Questions not as relevant for this semester are marked with an *) (Also: there will be a lot of questions on planetary atmospheres, why different planets have different volatile molecules in their atmosphere, the story of air and water)


1. Over another few billion years, the Sun is expected to brighten by about a factor of 2. Eventually, what planet might be most like Earth is now?
   (a) Mercury
   (b) Venus
   (c) Mars
   (d) Pluto
   
   
2. The role of nuclear fusion in a star like our Sun is to
   (a) make the stellar interior get very hot
   (b) keep the stellar interior at the same temperature
   (c) cool the stellar interior
   (d) explode the stellar interior
   
   
3. The planet Jupiter is mostly made of similar material as
   (a) any normal planet
   (b) any normal asteroid
   (c) any normal comet
   (d) any normal star
   
   
4. Which of the following is never retrograde in our solar system?
   (a) the rotation of a planet
   (b) the apparent (synodic) orbit of a planet
   (c) the actual (sidereal) orbit of a planet
   (d) the motion of comets
   
   
5. If you watch a comet in the sky for a minute or two, its ion tail can tell you
   (a) how fast the comet is moving
   (b) the direction the comet is moving
   (c) the direction to the Sun
   (d) the radiant of the associated meteor shower
   
   
6. If we found an asteroid in an elliptical orbit that carried it from near the orbit of the Earth to near the orbit of Mercury, its speed would
   (a) always be slower than the Earth
   (b) always be faster than Mercury
   (c) always be between the speeds of Earth and Mercury
   (d) sometimes be slower than Earth, sometimes faster than Mercury
   
   
7. A rocky planet that is seen to be heavily cratered is probably
   (a) fairly small for a planet
   (b) fairly large for a planet
   (c) relatively far from the Sun
   (d) relatively close to the Sun
   
   
8. *What comet can be seen by the naked eye in the night sky right now?
   (a) comet Holmes
   (b) comet Halley
   (c) comet Hyakutake
   (d) there are no comets currently visible
   
   
9. Imagine that from your front porch on the Spring equinox at midnight, you can see Polaris just above the point of a certain tree across the street. You go to bed and wonder, when is the next time you might see it in that same spot?
   (a) the next day at any time
   (b) the next night at any time
   (c) the next night at midnight
   (d) the next equinox at midnight
   
   
   
   
   
10. We only see comets for a few months at a time primarily because the rest of the time they are
    (a) too far away from us to see them
    (b) too far away from the Sun for them to be visible
    (c) on the other side of the Earth from us
    (d) they burn up after that
    
    
11. Where do the oxygen molecules in the Earth's atmosphere come from?
    (a) it leeched out from the water
    (b) it was released by plants and algaes
    (c) it was there when the Earth formed
    (d) it was created by human intervention
    
    
12. If you found a meteorite that was pure metal, you would assume that it
    (a) came from a large parent body that was totally shattered
    (b) came from a small parent body that was totally shattered
    (c) chipped off the surface of a large parent body
    (d) chipped off the surface of a small parent body
    
    
13. *The Moon is tidally locked to the Earth, but nevertheless its orbit is slightly elliptical (not circular), and the Moon spins at the same rate as it orbits. This means that from the Moon, the Earth will
    (a) always appear the same size and at the same point in the sky
    (b) always appear the same size, but will appear to move around slightly
    (c) stay at the same place in the sky but change slightly in apparent size
    (d) appear to be slightly different sizes and at slightly different places
    
    
14. *Which of the following list is the order that you would tend to find planetary materials as you go farther from the Sun?
    (a) metals, rocks, ices
    (b) ices, rocks, metals
    (c) rocks, ices, metals
    (d) rocks, metals, ices
    
    
15. *An asteroid can be in a circular orbit around the Sun with the same period as Jupiter's orbit if the asteroid
    (a) has recently broken off from Jupiter
    (b) is where there is the right mix of the Sun's gravity and Jupiter's
    (c) has as much mass as a planet
    (d) has the same distance to the Sun but a slower speed than Jupiter
    
    
16. *If the Earth was moved to a circular orbit that took 8 years to go around the Sun, by what fraction would its surface temperature change? (Hint: work backward from the answers, starting with the rate the Earth would emit heat, and finding the required distance to the Sun.)
    (a) 1/2
    (b) 1/4
    (c) 1/8
    (d) 1/16
    
    
17. Which of the following can still have a molten interior?
    (a) a planet very near the Sun because its surface is so hot
    (b) the moon of a gas giant, because it is close to a massive planet
    (c) a planet with a highly tilted axis, so its seasons are severe
    (d) a moon whose surface is heavily cratered
    
    
18. Solar flares can cause an Aurora Borealis because they
    (a) emit bright light
    (b) emit charged particles
    (c) cause the Sun to stay in equilibrium
    (d) cause dark areas called sunspots
    
    
19. What is the primary difference between a comet and an asteroid?
    (a) the shape of their orbit
    (b) how icy they are
    (c) both (a) and (b)
    (d) neither, they just look different from Earth
    
    
20. The surface temperature of the Sun is about 6000 K. If we heat it up to 20,000 K, it would emit primarily in the
    (a) ultraviolet
    (b) visible
    (c) infrared
    (d) x-ray
    
    
21. Which statement about the Earth's orbit around the Sun is most correct:
    (a) the Sun's gravity keeps the Earth from falling toward the Sun
    (b) the Earth's gravity keeps it from falling toward the Sun
    (c) the Earth does not fall, it has too much mass
    (d) the Earth is falling, but gets no closer because it also moves sideways
    
    
22. The most direct reason why the Sun would look very bright, if you went out right now and looked at it, is
    (a) it is very far away
    (b) its surface is at about 6000 K
    (c) its core is fusing hydrogen into helium
    (d) it is gradually collapsing under its own gravity
    
    
    
    
    
    
23. *The explanation for why Saturn has rings is directly related to the reason
    (a) trees form rings as they grow older
    (b) Saturn has a bent magnetic field
    (c) rainbows are bent like a ring
    (d) Jupiter's moons Io and Europa have heated interiors
    
    
24. *If a single point of light in the sky has a spectrum that has both a bright visible component and a bright infrared component, we might conclude it was
    (a) a very young version of our own solar system
    (b) a very old version of our own solar system
    (c) a solar system pretty much like ours is now
    (d) an alien spacecraft
    
    
25. * The key issue in determining if something sinks or floats is
    (a) its weight
    (b) its density
    (c) its size
    (d) whether or not it studies hard
    
    

Answers to form A:
(1-5): CBDCC
(6-10): DAABB
(11-15): BADAB
(16-20): ABBCA
(21-25): DBDAB