Creating a crater to constrain the age of an asteroid's surface

[Judi Lynn]

An important science goal for the Hayabusa2 mission is to map the history of asteroid Ryugu.

As a primitive carbonaceous asteroid from the early days of the Solar System, Ryugu’s life traces the movement of ices and organics; the ingredients for habitability.

With the majority of information about the asteroid gathered from detailed observations, a key question for constructing a chronology is the age of that observed surface. Dating of surfaces of celestial bodies is done by counting the size and frequency of craters. Comparing such counts with the expected rate of impacts yields a value for the surface age.

However, these age estimates can be very uncertain. The first assessment of the Ryugu surface suggested the asteroid had stayed in the asteroid belt (where collisions mainly occur) anywhere between 6 million and 200 million years: a range covering over an order of magnitude. This uncertainty is due to not knowing how the material of Ryugu’s surface responds to an impact. In particular, what force stops a crater growing?

More:
https://www.heritagedaily.com/2020/04/creating-a-crater-to-constrain-the-age-of-an-asteroids-surface/127192