http://www.npr.org/2013/03/29/175741693/segment-2
This one was from last week's "Science Fridays". It was a segment about collisions and their effects on our solar system.
The most interesting part was about the creation of the moon. I'd heard before that the moon might have been formed from part of the earth but I never really understood what that meant. In particular I always imagined that some solid object, like a comet or astroid, had hit the already solid earth and sent off a chunk which became the moon.
It turns out that this was a total misunderstanding. For one thing, if the collision took place, it happened while the earth was still somewhat molten. And it wasn't a collision with a small thing, it was a collision with another planet sized thing, which was also not solid.
Even more interesting it turns out that this model isn't really supported by some current evidence. Most of what the moon is made up of is the same stuff the earth is made up of. If it was formed by a collision of the earth and another planet then the moon should be made up of some of that other planet's material.
Despite this evidence, the scientists being interviewed said he'd "bet his career that some kind of a giant impact that formed the moon". He's just not sure what kind.
No comments:
Post a Comment