Volcanism on Vesta
When searching for a meteorite's source, experts can sometimes link a group of related meteorites to a type of asteroid or a region in the asteroid belt. Just one group, the HED meteorites—composed of the howardites, eucrites and diogenites—has been traced back to a specific asteroid, Vesta.
How do we know these meteorites came from Vesta? The composition of an asteroid's surface can be determined by the way it reflects sunlight. Vesta is the only large asteroid whose "light signature" matches the basaltic rock of the HED meteorites; each meteorite type matches a different part of Vesta's surface.
The three types of HED meteorites tell the story of the sometimes violent processes that shaped Vesta. The eucrites are hardened lava that flowed onto Vesta's surface; the diogenites come from rock buried deeper down; and the howardites are a mixture of the other two, created by impact mixing.
Keywords: Astrogeology, Astrophysics, Basalt, Magmas, Meteorites, Vesta (Asteroid)