These are the first two Earth analogs discovered by Kepler

Dec 21, 2011 14:51 GMT  ·  By
Kepler-20e (left) and Kepler-20f are the smallest exoplanets ever discovered
   Kepler-20e (left) and Kepler-20f are the smallest exoplanets ever discovered

Earlier today, I wrote a piece about the exoplanets Kepler-20e and Kepler-20f, which were found by the NASA Kepler Telescope about 1,000 light-years away. These objects, which you can now see in more detail, are the smallest exoplanets ever discovered.

In fact, one of them is smaller than Earth. Kepler-20e has a radius just 0.87 times that of our planet, whereas Kepler-20f is slightly larger, at 1.03 times the radius of Earth. Objects such as these two are the primary reason why Kepler was constructed in the first place.

NASA announced the planets yesterday, December 20, during a conference. Experts said that the two objects orbit extremely close to their parent stars, in just 6.1 and 19.6 days, respectively. This means that they are tidally locked to their parent star, Kepler-20, in the same way the Moon is tied to Earth.