How Many Earths: An Interactive GuideOctober 3rd, 2013
This interactive website from NewScientist explains what scientists look for when searching for exoplanets similar to Earth. The Kepler satellite has looked at over 150,000 candidate stars for habitable, Earth-like planets and found an estimated 51 “Earths” orbiting those stars. After extrapolating for planets in orbits that Kepler cannot detect, it is estimated that there are 22,500 “Earths” orbiting those 150,000 stars. However, those stars make up 0.28% of the sky and Kepler can only see 3,000 light years away. Therefore, the total number of “Earths” in the universe is estimated to be 15-30 billion!