Ultraviolet Radiation Key to Water in Space

While following up on some previous discoveries, a team of astronomers determined that water molecules in space can be produced simply in the presence of ultraviolet light.

The group was investigating findings made some time ago, when a massive cloud of water vapors, heated at high temperatures, was discovered around a massive star.

Because the celestial body was of the type known as carbon-rich star, researchers were at a loss in explaining how was it that the water formed. Molecules of the stuff rarely appear around such stars.

A variety of explanations were proposed, including that the clouds came from exploding comets and dwarf planets, that may have revolved around the giant star IRC+10216.

But the data collected from the location disagrees with such a proposal, mainly because the temperature of the water was found to be too high to support such a conclusion.

Using information collected recently by the European Space Agency's (ESA) Herschel Space Observatory, researchers discovered that ultraviolet light is in fact the only element needed to produce water in the vicinity of carbon-rich stars.

The presence of UV light alone is not the only “ingredient” necessary for the appearance of water molecules, but it is absolutely necessary.

This is the conclusions researchers at the Katholieke Universiteit Leuven, in Belgium, arrived at, after interpreting data collected by the PACS and SPIRE instruments aboard Herschel.

“This is a good example of how better instruments can change our picture completely,” explains experts Leen Decin, who was the lead author of the new investigation.

He reveals that telescope data indicate the existence of water molecules a lot closer to the massive star than comets would allow for. The celestial wanderers would be destroyed this close to the “fireball.”

The water molecules themselves were found to exist within temperature ranges extending from -200 degrees to 800 degrees Celsius.

Researchers explain that water molecules are formed within the massive dust envelope that contains the star itself. UV light coming in from surrounding stars hits the dust lumps, triggering chemical reaction that lead to the formation of water.

Most likely, investigators believe, carbon monoxide and silicon monoxide are broken apart, releasing oxygen atoms in the process.

These atoms can bind with hydrogen, to produce water. “This is the only mechanism that explains the full range of the water’s temperature,” Decin concludes.