Using Earth-based telescopes to measure the brightness of light reflected from Vesta, scientists can analyze the chemical composition of Vesta's surface. They have determined that it is likely composed of basalt, hardened lava that presumably oozed out of a hot interior.
This basaltic composition matches that of many meteorites found on Earth. Scientists believe that these meteorites broke off from Vesta.
This meteorite is a fragment of Vesta that flew into space during a collision.