Moon water blew in on solar wind

摘要

Almost all of the moon's water comes from the action of particles in the solar wind and not from the shattered remnants of water-rich comets and meteorites, as was once believed. So says a fresh analysis of lunar rock samples from two American moonshots. The Apollo missions painted a picture of the moon as a bone-dry desert. So astronomers were surprised when three probes in 2009 showed that a lot of water is locked up in minerals in the soil. There are three possible sources of that water. Comets and meteorites were a popular idea for a while. Another good candidate is the solar wind - the plasma that streams from the sun's upper atmosphere and smashes high-energy protons into the moon's surface. Cosmic rays from outside the solar system can also inject ions into lunar rocks, causing chemical changes that create water.