(Yes, my Spanish sucks.) The Dawn mission found signs of volatile materials—including water and elemental hydrogen—on the surface of the asteroid Vesta. Since Vesta is likely the source of a particular type of meteorite on Earth, the presence of volatiles was surprising, but intriguing. Vesta is remarkably like the terrestrial worlds (Mercury, Venus, Earth, Mars, and the Moon), with a layered internal structure and interesting surface features, so the probable discovery of water further hints at its connection to the planets.

The presence of volatiles on the asteroid—and especially hydrogen—suggests they were added to the asteroid later. This implies a common source for Earth’s and Vesta’s water, further cementing Vesta’s status as a terrestrial world in its own right. [Read more….]