The Sun Is Spraying Water Into Space

When the solar wind hits oxygen-rich rocks, water can form

SDO - AIA / NASA Earth Observatory

Our oceans, it is thought, came from space, as ice-rich comets rocked the early Earth. But some of that water, which set the conditions for life to arise, may have been born from the Sun.

On top of providing us with heat and light, and forming the gravitational basis of our solar system, the Sun is constantly pumping out a flow of ions known as the solar wind. Made up of charged particles, mostly the bare nuclei of hydrogen atoms, the solar wind streams out across the solar system, driving the aurorae, affecting the chemistry of our atmosphere and, according to a new study, sprinkling space with water.

When the solar wind blows against oxygen-rich rocks, says Charles Choi for, the combination of hydrogen and oxygen can cause water to form. This process could play out anywhere with the right types of rocks, from the surface of the Moon to a solitary mote of interplanetary dust. New Scientist:

As interplanetary dust is thought to have rained down on early Earth, it is likely that the stuff brought water to our planet, although it is difficult to conceive how it could account for the millions of cubic kilometres of water that cover Earth today. "In no way do we suggest that this was sufficient to form oceans," says Ishii.

But it could help explain why our solar system is actually quite wet.