TWO teams of astronomers have discovered the largest and farthest reservoir of water ever detected in the universe. Looking from a distance of 30 billion trillion miles away into a quasar-one of the brightest and most violent objects in the cosmos - the researchers, led by scientists at the California Institute of Technology (Caltech), have found a mass of water vapour thats at least 140 trillion times that of all the water in the worlds oceans combined, and 100,000 times more massive than the sun. Because the quasar is so far away, its light has taken 12 billion years to reach Earth. The observations therefore reveal a time when the universe was just 1.6 billion years old. The environment around this quasar is unique in that its producing this huge mass of water, says Matt Bradford, a scientist at NASAs Jet Propulsion Laboratory (JPL), and a visiting associate at Caltech. Its another demonstration that water is pervasive throughout the universe, even at the very earliest times. Bradford leads one of two international teams of astronomers that have described their quasar findings in separate papers that have been accepted for publication in the Astrophysical Journal Letters. A quasar is powered by an enormous black hole that is steadily consuming a surrounding disk of gas and dust; as it eats, the quasar spews out huge amounts of energy. Both groups of astronomers studied a particular quasar called APM 08279+5255, which harbours a black hole 20 billion times more massive than the sun and produces as much energy as a thousand trillion suns. Since astronomers expected water vapour to be present even in the early universe, the discovery of water is not itself a surprise, Bradford says. IW