Scientists have come up with an answer to how water comes about in the interstellar clouds that give birth to stars, planets, and life, by suggesting that tiny grains of cosmic dust in the clouds help in the process.

According to a report in New Scientist, though water forms easily when hydrogen and oxygen exist as gases, models of interstellar clouds suggest that this route is unlikely to produce the abundance of water seen in them.

Most of the water that is seen has formed icy sheaths around tiny grains of dust in the clouds, and it is believed oxygen atoms accumulate on the grains and react with hydrogen to form water.

Now, Akira Kouchi and colleagues at Hokkaido University in Sapporo, Japan, have tested the idea by freezing oxygen onto a nucleation surface held at 10 degrees above absolute zero.

When they fired atoms of hydrogen onto the oxygen, hydrogen peroxide was produced, which in turn reacted with more hydrogen to produce water.

These reactions happened fast enough to explain the amounts of water found in interstellar clouds.