Astronomers have detected water in the atmosphere of a planet outside our solar system for the first time.
The discovery, announced today, means one of the most crucial elements for life as we know it can exist around planets orbiting other stars.
“We know that water vapor exists in the atmospheres of one extrasolar planet and there is good reason to believe that other extrasolar planets contain water vapor,” said Travis Barman, an astronomer at the Lowell Observatory in Arizona who made the discovery.
HD209458b is a world well-known among planet hunters. In 1999, it became the first planet to be directly observed around a normal star outside our solar system and, a few years later, was the first exoplanet confirmed to have oxygen and carbon in its atmosphere.