Kepler-20e: Alien Planet Smaller Than Earth
NASA capped the year 2011 as it began, with the announcement of Kepler-20e, the smallest alien planet yet found, which orbits a star 950 light-years from Earth.
Kepler-20e is only about 87 percent the width of Earth. It is 6,900 miles wide. The Earth is about 7,900 miles wide.