NASA/Ames/JPL-Caltech

This artist's conception illustrates Kepler-22b, a planet known to comfortably circle in the habitable zone of a sun-like star. It is the first planet that NASA's Kepler mission has confirmed to orbit in a star's habitable zone -- the region around a star where liquid water, a requirement for life on Earth, could persist.

Astronomers have long suspected that there were other earth-like planets in the universe. Given the vastness of space, there very well may be millions of them - but hard evidence of their existence was elusive until NASA’s Kepler mission began cataloging them in 2009.

Now, Kepler researchers have presented the discovery of Kepler-22-b, the smallest planet yet discovered orbiting a star’s “habitable zone” – the distance where conditions are favorable for life, including the possibility of liquid water. The Kepler team tracks planets by measuring the shadows produced as they orbit stars and they’ve discovered 2,326 planet candidates to date. But don’t start packing... the newest member of the planetary family is 600 light years away, which means that humans won’t be traveling there anytime soon.

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Should NASA be devoting more resources into the discovery of habitable planets?

Guest:

Nick Gaultier, Kepler Project scientist, NASA’s Jet Propulsion Laboratory