On the possibility of two Moons for the early Earth

There is an interesting new theory that Earth may have had two moons earlier on and the smaller moon merged into the big one. This collision may explain the difference in the features between the dark side and front side of the Moon (with respect to us: we only see one side of the Moon from the Earth). Here is a short podcast on the topic with Monte on WRSI - The River.

In addition, we also played a game on the National Geographic website where you can create your own solar system around your own favorite star. It is actually pretty cool. You can play with various properties of the star and the planets (including their orbits) to see how long they survive. Check out the Solar System Builder here.

Listen to the full podcast here: On two moons and playing god.