Nature: Just weeks after Dawn left orbit around Vesta, papers are being published based on data the spacecraft obtained. Two articles by the Dawn research team reveal evidence for the existence of water on the asteroid. The first paper reveals concentrations of hydrogen in the equatorial regions that suggest the water content is as high as 400 parts per million. The second paper identifies pits up to 200 m deep that could have been caused by the venting of water vapor into space. The researchers believe the water could have been stored in hydrated minerals on smaller, water-rich asteroids that impacted Vesta. Later impacts would have heated the minerals, releasing the water vapor.