There are about 200 billion stars in our galaxy, with 40 billion of them like our sun, Marcy said. One of his co-authors put the number of sun-like stars closer to 50 billion, meaning there would be at least 11 billion planets like ours. Based on the 1-in-5 estimate, the closest Earth-size planet that is in the habitable temperature zone and circles a sun-like star is probably within 70 trillion miles of Earth, Marcy said. And the 8.8 billion Earth-size planets figure is only a start. Thats because scientists were looking only at sun-like stars, which are not the most common stars. advertisement An earlier study found that 15 percent of the more common red dwarf stars have Earth-size planets that are close-in enough to be in the not-too-hot, not-too-cold Goldilocks Zone. Put those together and thats probably 40 billion right-size, right-place planets, Marcy said. And thats just our galaxy. There are billions of other galaxies. Scientists at a Kepler science conference Monday said they have found 833 new candidate planets with the space telescope, bringing the total of planets theyve spotted to 3,538, but most arent candidates for life. Kepler has identified only 10 planets that are about Earths size circling sun-like stars and are in the habitable zone, including one called Kepler 69-c. Because there are probably hundreds of planets missed for every one found, the study did intricate extrapolations to come up with the 22 percent figure — a calculation that outside scientists say is fair. Everything theyve done looks legitimate, said MIT astronomer Sara Seager. 竅 First published November 4th 2013, 4:43 pm Dying Star Gives Birth to a Cosmic Diamond Ring ESO ESO Nov 04 an hour an hour SPACE
Posted on: Wed, 09 Apr 2014 14:39:21 +0000