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. And some 500 million of those planets are in what is known as the Goldilocks zone, where the climate is thought to be not-too-hot and not-too-cold, and life could exist. The numbers were extrapolated from the early results of NASA's Kepler telescope, almost two years though a three-and-a-half year mission which has cost an estimated $600million. 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. (Daily Mail)