March 6, 2012 10:10
Scientists believe that only in our galaxy — the Milky Way — there may be hundreds of billions of planets.
Scientists preliminary results of a fascinating study, which has recently become very fruitful. Specifically, has mapped the Milky Way, and counted the number of open exoplanets — that is, those who are outside the solar system, orbiting other stars — near and far. And it turned out that the number is, well over a thousand, are too large.
Only NASA's Kepler space telescope (Kepler) for only 136 days of work in 2011, discovered in 1235 exoplanets. And this is after a survey of a relatively small portion of our galaxy — the Milky Way. In sight got not more than four of the celestial sphere. Specifically, is the area where the constellation Cygnus.
Astronomers explicit "bust" with exoplanets not surprised. On the contrary was the basis for the revolutionary and mass conclusions. They came representatives of dozens of research institutes and universities around the world, publishing them — their findings — in the journal Nature. And now, apparently, have to accept that the universe is much more planets than stars. And not vice versa, as previously thought — even 20 years ago, believing that the world of the stars — is a rarity. If it is not fiction.
— Planet, at least in our galaxy — the Milky Way — are more common than stars, — says Arnaud Cassan of the Institute of Astrophysics in Paris. — And they are usually small — comparable in size to the Earth.
According to astronomers, working with Cassani at the European Southern Observatory, every star has at least one planet. But usually — more of them. And in about ten billion stars in our galaxy, the planets are in the so-called habitable zone. Located at a comfortable distance from the star, which provides suitable conditions for life. And most importantly — the possible existence of liquid water.
First, scientists were more modest in the estimates. For example, Michelle Govanlok (Michael Gowanlock) University of Hawaii (University of Hawaii's), a statistical analysis based on its computer model called "Model of habitability within the Milky Way» (Model of Habitability Within the Milky Way Galaxy) assures that only 1.2 percent of stars must have a habitable planet. And their number is estimated at one billion. Now assume that habitable worlds may be 10 times greater.
Found the second Mars
NASA's Kepler space telescope (Kepler) continues to delight astronomers. And to put a record. Recently, thanks to him, managed to find planets that are smaller than our Earth — 0.87 and 0.76 of its diameter. But now the system KOI-961 detected a planet with a diameter of 0.57 Earth. It — a sort of Mars.