Here are the first planets discovered by Kepler satellite
Kepler The satellite, launched by NASA in March 2009, began to bear fruit. The heads of the space mission, seeking planets outside our Solar System , have announced the first discovered last Monday at the annual meeting of the American Astronomical Society, held recently in Washington.
Five new planets orbiting distant stars 100 light years from our Sun, have been identified during the first months of observations made by Kepler, and should thus be added to the ranks of extra-solar planets already discovered so far, which amounts to over 400. This progress, achieved only in the last 15 years, astronomers can better understand how planets and planetary systems like ours, are formed around stars.
The new worlds discovered by Kepler are very different from our planet: they are much larger and very hottest of the Earth. Four of them are even larger than Jupiter, the largest of the planets at the court of the Sun, and only one of them is slightly smaller, closer in size to another giant of the Solar System, Neptune.
Because of their high temperatures of over 1200 degrees, to assume that these planets harboring life forms type "earth" is virtually impossible. The purpose of the Kepler mission is more ambitious, however: in the next three years of observations it is likely that astronomers are able to detect any planets similar to ours, in some corner of our galaxy.
The fact that the first planets discovered to be the Giants is a "disadvantage" of the method used to find them. In fact, Kepler uses the technique known as "transit" when a planet passes in front of the star around which it rotates, it becomes obviously less bright, because its light is obscured by the planet. Looking at hundreds of thousands of stars for a long time, astronomers study how their brightness varies and so can detect the presence of one or more planets around them.
longer a planet, the greater will be its marked darkening of star and, therefore, easier discovery. But size is not everything, even the distance from the star is very important. All these worlds are very close to their sun, and to make a full orbit around it only takes a few days, in comparison, the Earth takes one year, and Mercury, the closest planet to our Sun, it takes approximately three months for complete a so-called revolution.
The proximity of these planets to their host star is yet another factor that facilitates the discovery, orbiting around it so fast, the obscure quite often, so it is very likely that the darkening is noticed by astronomers in time observation compatible with those rights. A planet that take months or years to complete one orbit around its star is rather elusive, but not entirely impossible to detect.
"It's just a matter of time," said Jon Morse, director of the Astrophysics Division at NASA Headquarters in Washington. "Future observations with Kepler will find planets with orbits larger and larger until they finally find an analogue of the Earth."
Discovering planets located at distances of "reasonable" by the star around which they orbit is a crucial step in search of other worlds that they could theoretically accommodate life forms. The so-called "habitable zone" defines the exact distance, around a star where the temperature is enough to guarantee the existence of liquid water on the surface of a planet. For our sun, this distance corresponds to the orbit of the Earth: the farther or closer, and the life "as we know it" would not have been possible.
None of the 400 planets discovered so far is in the "habitable zone" of its star, but astronomers are confident in Kepler and hope that someone will be able to identify in the next few years. But the question of the existence life in the universe does not end in the search for life forms similar to those on our planet. "In other parts of this universe, it is easy to achieve, there is all that I still can not imagine," sang Bluvertigo a decade ago. Let us surprise dall'inimmaginabile.
CLAUDIA MIGNONE
In the top, the five new planets discovered by Kepler satellite, and their size, compared with those of Jupiter and the Earth below, a one rappresenzatione Art of five new worlds uninhabitable. Source: NASA / JPL-Caltech / T. Pyle (SSC)
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