The solar wind makes water using space dust

24 Jan 2014

At ... water ice is the most abundant solid material in the universe. Much of it is produced as a by product of star formation - but not all of it (it seems). John Bradley and colleagues at the John Livermore National Laboratory have found a new souce of water in our solar system. The solar wind seems to be creating water on dust in space, the plentiful dust between the planets of the solar system. They are saying that such dust, as well as tiny meteorites, can be eroded by the solar wind. The bombardment of the Moon, by the solar wind and tiny meteorites causes space weathering. On Earth, the atmosphere protects us from the meteorites while the magnetic field can deflect the solar wind. Lunar dust (made of silicates) shwo chemical modifications caused by high energy impact by the solar wind. This leads to a lowering of the bonds between oxygen and hydrogen atoms in these silicates - suggesting water can be formed in the process (or at least modelled on the computer). Water requires two atoms of hydrogen and one of oxygen. If silicates can provide one of each we still don't have water - but conveniently, hydrogen atoms are available in the solar wind. The paper is published by PNAS (see or

Bradley's work implies that water molecules are being formed all the time - on inter planetary dust particles, or on the Moon, and even on asteroids. However, such a process can never account for all the water in the solar system. It is being produced elsewhere and most of it is still thought to have been a leftover of star formation.