Pristine fragments of asteroid breakup
By Ron Cowen
Planetary scientists have for the first time precisely dated a collision that smashed an asteroid into fragments. The breakup is so recent–just 5.8 million years ago–that the pieces probably haven’t been altered by contact with one another, other space debris, or cosmic rays.
These pristine fragments could reveal how easily an asteroid breaks apart and whether a space rock on a collision course with Earth could be destroyed by a nuclear blast. The fresh collision may also shed light on planet formation, notes David Nesvorny of the Southwest Research Institute in Boulder, Colo.