11 Best Astronomy Stories of 2011

Alien Planets in the Habitable Zone

NASA/Ames/JPL-Caltech

On Dec. 5, researchers announced that NASA's planet-hunting Kepler observatory confirmed the discovery of its first alien planet in the habitable zone of its parent star. This so-called habitable zone is located at just the right distances away from the star so that conditions could allow liquid water to exist on a planet's surface.

But Kepler is not alone in its hunt for alien worlds.

A telescope from the European Southern Observatory that searches for signs of exoplanets also made enticing finds this year. The High Accuracy Radial velocity Planet Searcher instrument, or HARPS, found more than 50 new alien planets, including one super-Earth that could potentially support life.

As researchers continue to sift through data from Kepler, HARPS and various other instruments, exoplanet research is not showing any sign of slowing down.

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