Astronomy 100

Section 2, Fall 2008

Homework F

Due Wednesday, October 22

On your scantron fill out your NAME, STUDENT NUMBER, and NETWORK ID both in writing and in the bubbles. In addition, fill out "FORM F."


1. We can measure the age of Venus's surface from
a) radioactive dating of rocks
b) the number of craters
c) nothing; it is not possible
d) the rate of erosion
e) the amount of water in Venus's atmosphere

2. Which body has the largest iron core relative to its mass?
a) Mercury b) Venus c) Earth d) Moon e) Mars

3. The atmospheres of Venus and Mars are dominated by
a) nitrogen
b) helium
c) hydrogen
d) methane
e) carbon dioxide

4. Venus's clouds are made of
a) oxygen
b) carbon dioxide
c) nothing, there are no clouds
d) sulfuric acid
e) water vapor

5. The pressure at the bottom of Venus's atmosphere is how many times that at the bottom of Mars's atmosphere?
a) 10,000 b) 1000 c) 100 d) 10 e) 1

6. Most the Earth's carbon is in its
a) atmosphere
b) crust and mantle
c) solid core
d) liquid core
e) oceans

7. In what way is Mars similar to the Earth?
a) polar caps
b) seasons
c) rotation period (length of day)
d) all the above
e) none of the above

8. The "canals" of Mars are
a) optical illusions
b) real canals
c) natural rivers
d) roads
e) impact features

9. Where is most of Mars's water now?
a) in the polar caps and crust
b) in liquid oceans
c) it is all in the atmosphere
d) there isn't any at all
e) mixed into the iron core

10. Evidence that a thick atmosphere once surrounded Mars comes from
a) old river beds
b) polar caps
c) life
d) volcanos
e) the lack of impact craters on the surface

11. The evidence for life on Mars
a) is presently weak or non-existent
b) consists of live single-celled organisms
c) consists of confirmed fossils of single-celled organisms
d) is a statue of Elvis
e) consists of fossilized footprints

12. Mars's volcanos have grown large because
a) Mars is hotter than Earth
b) Mars has no water
c) there is too little air to erode them away
d) there is little or no plate motion (that is, continental drift)
e) there have been few meteorite impacts to wear them away

13. The visible clouds of Jupiter are made of
a) ammonia b) methane c) water d) hydrogen e) sulfuric acid

14. Jupiter and Saturn are made mostly of
a) molecular hydrogen gas
b) helium gas
c) liquid molecular hydrogen
d) silicate rock
e) water ice

15. The magnetic fields of Jupiter and Saturn are produced by circulation of their
a) atmospheres
b) liquid iron cores
c) liquid metallic hydrogen interiors
d) storm systems
d) silicate mantles

16. Io is hot and has many volcanoes because
a) it is very radioactive
b) it receives X-rays from its parent planet
c) it is continually hit by meteorites
d) of its planet's magnetic field
e) of tidal flexing

17. The surfaces of Ganymede and Europa are mostly
a) dry ice
b) water ice
c) methane ice
d) carbon monoxide ice
e) rock

18. Which satellite seems to have methane lakes?
a) Titan b) Io c) Ganymede d) Callisto e) Europa

19. If you doubled the mass of Saturn by adding hydrogen,
a) you would crush the planet to a smaller size.
b) Saturn would explode
c) you would compress Saturn's hydrogen into iron
d) nothing would happen
e) you would slightly increase the radius, but mostly increase the density.

20. Saturn's rings are made of
a) ice coated rocks a few centimeters to meters in diameter
b) methane gas
c) a solid sheet of rock
d) hydrogen gas
e) ammonia clouds

21. Jupiter's average chemical composition is most like that of
a) the Moon b) the Sun c) Earth d) Mars e) Venus

22. Which planet is tilted by nearly a right angle to its orbital plane?
a) Neptune b) Mercury c) Uranus d) Saturn e) Earth

23. Why do we believe that Uranus has a relatively larger rocky core than Saturn?
a) We see mountains on its surface
b) Direct observation of silicates
c) Uranus's satellites orbit faster
d) Uranus is small for its mass compared with Saturn
e) The atmosphere is made of a silicate gas

24. Neptune has "captured" which bodies?
a) Titan and Triton
b) Ganymede and Callisto
c) Pluto and Triton
d) Pluto and Uranus
e) Uranus and Saturn

25. What is odd about Pluto?
a) highly tilted orbit
b) relatively large satellite
c) very eccentric orbit
d) all of the above
e) none of the above