THE early solar system was probably wetter than we thought. Quartz veins found in a meteorite indicate that water was present 4.4 billion years ago on Vesta, the brightest of the asteroids in the main belt.
Minerals containing water have been spotted on the largest main-belt asteroid, Ceres, but Vesta’s spectrum shows no trace of water. About 520 kilometres wide, Vesta is covered with volcanic basalts. These are also found in so-called “HED” meteorites, which are thought to have been blasted off Vesta by past impacts. Most HED meteorites are bone dry, but now Allan Treiman of the Lunar and…
