1. Briefly describe a scientific theory explaining why Mercury has such a large iron core. 2. Astronomers often refer to Venus as Earth’s twin. What physical properties do the two planets have in...

1. Briefly describe a scientific theory explaining why Mercury has such a large iron core.

2. Astronomers often refer to Venus as Earth’s twin. What physical properties do the two planets have in common? In what ways are the two planets dissimilar?

3. Why is it hotter on Venus than on Mercury?