Select all that apply. Which of the following can be explained by colliding worlds in the early solar system?
A. Mercury's large metallic core
B. Venus's slow, backward rotation
C. Earth's tilted rotation axis and moon
D. Mars's asymmetric northern and southern hemispheres and Tharsis bulge

Select all that apply. Mercury does not have shield volcanoes, but if it did the largest ones would likely be similar in height to the largest ones on:
A. Venus
B. Earth
C. Mars

Select all that apply. Which is the following statements is true?
A. Since Venus is closer to the sun than Earth, its surface was hotter and consequently its water vapor could not condense into oceans, but instead remained atmospheric. Since water vapor is a greenhouse gas, this increased Venus's surface temperature.
B. Since Venus did not have standing water to help incorporate its atmospheric carbon dioxide into rocks, it remained atmospheric. Since carbon dioxide is a greenhouse gas, this increased Venus's surface temperature.
C. Earth's oceans help to incorporate Earth's atmospheric carbon dioxide into rocks. This is balanced by plate tectonics and volcanic activity, which returns carbon dioxide to Earth's atmosphere.
D. Since Mars is farther from the sun and smaller than Earth, its interior cooled more quickly, resulting in no plate tectonics and reduced volcanism.
E. Carbon dioxide in Mars's early atmosphere was absorbed by standing water and incorporated into rocks, but was not fully replenished by Mars's less active volcanoes. Since carbon dioxide is a greenhouse gas, this decreased Mars' surface temperature.
F. As Mars's surface temperature dropped, water vapor froze out of Mars's atmosphere. Since water vapor is a greenhouse gas, this further decreased Mars's surface temperature.