Name: _________________________________       Section Number: ______

Throughout this part of the course, we have looked at the planets of our Solar System, and the small bodies that attend them. Though they display a huge range of properties, we can understand this range in terms of the basic properties of the planets, their atmospheres and their surfaces. With this in mind, please answer the following three questions in a paragraph or two each (using complete sentences, of course).

A) (10 pts) Briefly explain why size is the most important factor influencing the surface appearance of the terrestrial planets (and large satellites). In your answer, be sure to

i) State the influence of planetary size on all four basic geological processes discussed in class.

ii) Give an example of two terrestrial planets in our solar system that are approximately the same size but, surprisingly, have different surface geology. Explain why the two objects have such different surfaces.

B) (8 pts) In all planets that have atmospheres, we see clouds. For example, the clouds of Venus appear greenish-white; Earth clouds are white, Jupiter has white, brown, and even red clouds, Neptune has a vivid blue-green color. Pick a pair of planets with very different cloud features and explain why the clouds look different on each planet. For each planet be sure to mention the main constituent of its atmosphere and that of the clouds we see.

C) (7 pts) Impacts of bodies larger than 100m in diameter produce craters on the surfaces that they hit. We see a large number of craters on the surfaces of most satellites of the planets, and on most planets, yet we see few on the surface of the Earth. Why don't we see lots of craters on the land surfaces of Earth?