Posted: Sun, Jul 15, 2001, 11:36 AM ET (1536 GMT)

An orbiting spacecraft has uncovered the first direct evidence of water in an extrasolar system, astronomers said last week. Astronomers said that observations by the Submillimeter Wave Astronomy Satellite (SWAS) detected a cloud of water vapor around a dying star, CW Leonis. That cloud of water vapor, astronomers conclude, is likely created as the star, growing brighter in the final stages of its life, is vaporizing several hundred billion icy bodies in a disk similar to the Kuiper Belt around the Sun. The discovery is the first time water has been detected in any kind of extrasolar planetary or protoplanetary decision, and surprised astronomers who did not expect to find water around a star of this type. Astronomers also said these observations could be a preview of what will happen to our Sun in five billion years when it evolves into a red giant.