Cosmic census finds crowd of planets in our galaxy Feb 19, 5:23
PM (ET) By SETH BORENSTEIN WASHINGTON (AP) - Scientists have
estimated the first cosmic census of planets in our galaxy and
the numbers are astronomical: at least 50 billion planets in the
Milky Way. At least 500 million of those planets are in the not-
too-hot, not-too-cold zone where life could exist. The numbers
were extrapolated from the early results of NASA's planet-
hunting Kepler telescope. Kepler science chief William Borucki
says scientists took the number of planets they found in the
first year of searching a small part of the night sky and then
made an estimate on how likely stars are to have planets. Kepler
spots planets as they pass between Earth and the star it orbits.
So far Kepler has found 1,235 candidate planets, with 54 in the
Goldilocks zone, where life could possibly exist. Kepler's main
mission is not to examine individual worlds, but give
astronomers a sense of how many planets, especially potentially
habitable ones, there a