Jeffrey Andrews-Hanna

Mars, without a big Moon, its spin axis goes up and down the full 90 degrees.

You can have the poles of Mars pointing straight at the Sun.

You can have the equator of Mars pointing straight at the Sun.

Because Mars has enormous, enormous climate changes, the kind of thing that we'd be pretty hard-pressed to deal with here on Earth.

So I'd say the moon has an important influence on life on Earth today.

And then, of course, who knows what our planet would look like without that impact?

That's anybody's guess.

Absolutely.

And one thing that we do have going for us, all of our samples are from a fairly small patch on the near side of the Moon, except for lunar meteorites.

It turns out there's meteorites that you can pick up on the surface of the Earth that actually got launched off of the surface of the Moon.

We don't know where those came from, but we think they'd be more or less randomly distributed.

So that's the one way we can sample the far side of the Moon, is by looking at these meteorites and saying, well, statistically, half of them should come from the far side.

The problem is, unlike the Apollo samples, where we know exactly where those were picked up, each meteorite could be from anywhere.

So there's a lot of interest in getting samples from the far side.