Regina Barber

So the moon could have just been made the same way Earth was made in this planetary disk around the sun.

All this rock and debris like clumping together.

Think of the sun and having rings like Saturn.

Colliding into each other, totally.

Yeah.

So there's another hypothesis I talked about with Tab Preisel, a planetary scientist also at Purdue.

Yeah.

But Tab did add that this idea of moon capture has mostly been ruled out.

Well, okay.

It's because there's all this evidence that the moon and the Earth are very similar, rather than being completely unique bodies that ended up orbiting the other by accident.

An early hint of this came from the Apollo missions from 1969 to 1972.

They brought back samples of the lunar rock to be studied, and those samples revealed that the Earth and the moon have almost identical chemical and elemental compositions.

Wow.

Yeah, yeah.

And, of course, how it happened exactly is still being studied.

Here's Tab again.

Yeah, there's one other hypothesis that takes into account the very similar composition between Earth and the moon.

This one suggests Earth spinning so quickly when it was forming that stuff just like flew off.

So imagine like I'm spinning on ice or something and I'm spinning so fast that my arm just flies off.

And your arm would become your moon.