The Kepler team recently announced the discovery of two new extrasolar planets, Kepler-20e and Kepler-20f. These planets are the first planets discovered beyond our Solar System approximately the size of the Earth. Kepler-20e is a little smaller than the Earth, with a radius 0.87 times that of the Earth, while Kepler-20f is a little bigger, with a radius 1.03 times that of the Earth. What sets these two planets apart from the Earth are their distances from their star. Although their host star, Kepler-20a, is a Sun-like star, the two planets have very small orbits, completing their paths around the star in just a matter of days. Kepler-20e completes its orbit in just 6.1 days and Kepler-20f does its in 19.6 days. The close proximity to their star makes their surfaces extremely hot, and likely inhospitable to life.
The Kepler-20 system is located about 1000 light years away. With the discovery of these two planets, the total number of known planets orbiting around Kepler-20a has risen up to 5.
Image Credit: NASA/Ames/JPL-Caltech