ScienceWhat can scientists learn from a stray SpaceX rocket crashing into the moon?

A leftover component from a SpaceX rocket has struck the moon, in an impact astronomers had predicted. The Falcon 9 upper stage was left drifting through space after carrying two lunar landers toward the moon. It was not designed to hit the lunar surface, but its eventual trajectory placed it on a collision course. Astrophysicist and cosmologist Brad Tucker discusses what researchers may learn from the impact.