This is CBS. I on the world. I'm John Batchel. Hotel Mars. Episode N. My colleague and co-pilot David Livingston of the space show is here.

We're going to the Czech Republic and then we're going to the asteroid belt. Thanks to Miroslav Brosh of Charles University. He is in the Czech

Republic, and he has identified the asteroid belt as the source of meteorites falling

to earth that permit him and his colleagues to date and to identify where those meteorites come from

and several events that took place in the asteroid belt

several million years ago.

Big, big thing events.

Bodies larger than 30 kilometers, some 100 kilometers.

Miroslav, it's a wonderful article you have in Nature magazine.

So the asteroid belt between Mars and Jupiter, what events took place that you can date and point

to where it happened?

How do you do this?

Good evening to you.

Good evening.

And let me explain that, you know, we studied the asteroid belt for a long time.

With my colleagues, we know essentially all asteroids and all groups of asteroids in the asteroid belt.

So I was very happy to collaborate with Pierre Vernazza and Michal Marseid,

because they are able to observe spectra of asteroids,

and they are able to recognize asteroids which are similar to meteorites.

They have similar spectra as the meteorites.

So that was our first guide.

And the second guide was to choose a suitable asteroid family,

...