Scientists have for the first time discovered water-ice and organic materials on the surface of an asteroid. The discovery provides evidence for the theory that asteroids could be the source of Earth's water. More info at Nature.
A slushy cocktail of water-ice and organic materials has been directly detected on the surface of an asteroid for the first time. The finding strengthens the theory that asteroids delivered the ingredients for Earth's oceans and life, and could make astronomers rethink conventional models for how the Solar System evolved.
It has long been thought that asteroids, which lie in a belt between Mars and Jupiter, are rocky bodies that sit too close to the Sun to retain ice. By contrast, comets, which form further out beyond Neptune, are ice-rich bodies that develop distinctive tails of vaporized gas and dust when they approach the Sun. However, this distinction was blurred in 2006 by the discovery of small objects with comet-like tails in the asteroid belt, says astronomer Andrew Rivkin of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.