Recall from Chapter 1 that Earth and Venus are so similar in size and overall composition that they are almost “twins.” Why did these two planets evolve so differently? Why is Earth's atmosphere rich in oxygen and poor in carbon dioxide, whereas the reverse is true on Venus? What would happen to Earth's oceans if Earth were a little bit closer to the Sun?

Question

anonymous · Answer

lol "Recall from Chapter 1"

Earth is in the habitable zone unlike Venus!

matt101 · Answer

All has to do with proximity to the sun. If earth was any closer to the sun, all the oceans on earth would dry up. Without water, there would be no plants, and as you probably know, plants produce much of the oxygen in our atmosphere from carbon dioxide.

Venus is too close to the sun, so it can't support water in its liquid form because it's too hot. Without water, there are no plants. Thus carbon dioxide is never converted to oxygen, and the composition of the atmosphere on Venus reflects that.

I'm no astronomer, but I think that makes sense :)

anonymous · Answer

Thank you, I was looking through my textbook and could not find the info for the life of me. LOL I definitely appreciate the help :)