G. Venus and Earth are about the same size and mass, yet carbon dioxide is a major constituent of the atmosphere of Venus, while oxygen is much more abundant in the Earth's atmosphere. Explain why the atmospheres are so different.
h. Explain why there are two general families of planets, rocky terrestrial and gaseous jovian.
i. The first planets discovered since ancient times were Uranus and Neptune. Compare how they were discovered.
j. What knowledge do comets and asteroids provide to studies of the origin of the solar system?
g. The differences most likely arose from small initial differences in the initial temperatures and atmospheric concentrations of carbon dioxide and oxygen. Studies have shown that several billion years ago the atmosphere of Venus was very similar to that of Earth today, and that there was likely a large amount of liquid water on its surface. Venus appears to have suffered a 'runaway greenhouse effect' where the carbon dioxide in the atmosphere lead to an increased planetary temperature, which freed trapped carbon from the oceans, increasing the amount of carbon dioxide in the atmosphere, which in turn increased the temperature, etc. ...