Thursday, February 4, 2010

Watery "Super Earth" spotted 40 light years from us

Our collection of exoplanets continues to expand and, in recent years, some dedicated hardware like CoRoT and Kepler have joined the search in space. But the latest discovery comes from some pretty mundane hardware—a collection of 40cm telescopes—and has some very compelling properties: a super earth that's likely to harbor liquid water, and orbits a star that's close enough to allow current observatories to image its atmosphere.

The results come courtesy of the MEarth project (a description is available via the arXiv), which is based on Mount Hopkins in Arizona. Instead of exotic, high-end optics, MEarth relies on eight 0.4m telescopes that can be pointed independently. The project works because the hardware is pointed at a very carefully chosen collection of stars: about 2,000 nearby M-dwarfs, which, as the name implies, are relatively small stars. That means that even a moderate-sized planet orbiting one will occlude a significant fraction of its surface during transit. The MEarth scopes are able to spot anything that blocks more than a half of a percent of the light as it transits in front of its host star.

Read the rest of this article...

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