Jeffrey Andrews-Hanna

This is something that we don't understand, and this is the most basic aspect of the moon.

In this sense, I think lunar science is very similar to Earth science back in the days before we understood plate tectonics.

So plate tectonics is how

Our continents drift around, how ocean basins form.

Plate tectonics is fundamentally what drives and explains the Earth.

Well, this near-side, far-side asymmetry is in many respects the most fundamental aspect of the moon, and we still can't explain it.

And then just this overall question of what drives early lunar dynamics?

Why do we see all these dikes formed?

Why was the early moon expanding?

Why was there rifting around the prosolarum region?

Another big question, why was there a magnetic field on the moon?

This is something I didn't talk about, but something my postdoc Alex is working on.

The early moon had a magnetic field very much like the Earth's.

And the troubling thing is that magnetic field was too strong, it was active for too long, and we can't come up with a mechanism to explain that.

And that is a big question that still needs to be answered.

And so I just want to wrap up then by saying the Moon is an incredible place.

We have incredible data from the Moon, not only gravity data, topography, images, all sorts of remote sensing data sets,

We're learning all sorts of things about the moon, about the lunar surface, as well as about the lunar interior.

And yet still, more than 50 years after people walked on the moon, we're still grappling to understand some of these fundamental questions.

And so that's, in my mind, why lunar science is still an exciting field.