GD 61 is a white dwarf star in the constellation Perseus, 150 light years from Earth, which supports a planetary system.[2] An asteroid in the system was detected in 2013 which contains water, the first detection of solid or liquid water on an extrasolar body. The asteroid, the first extrasolar asteroid detected, is 26% water by mass, close to the water content of asteroid Ceres. This evidence suggests that a planet, with a rocky surface similar to Earth's, may have existed in the past, with the asteroid thus being an artifact from this period, now possibly part of a debris field from the hypothetical planet's breakup. Such a planet would have had both a rocky surface and water, two key ingredients for life.[3][4][5]
Detection
Data from NASA's Hubble and FUSE telescopes, and from the Keck Observatory in Hawaii, were used to detect and observe the asteroid.
