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This article was published May 11, 2016 at 15:11 hours.
the last change is the May 11, 2016 at 15:27.
Kepler has given us with its new planets discovered neighbors, in 1284 to be precise of which at least 9 may be similar to Earth. Obviously we’re not talking about the famous astronomer who in the first two decades of the 1600s found the laws to which the planets revolving around the Sun, including Earth, must, obey, but NASA probe specialized in the hunt for planets revolving around stars instead to us nearby.
exoplanets already there had given away 2,000 in previous years but now, at a press conference and announced rightly held with tones of satisfaction and pride, American scientists tell us that the total number of planets that Kepler has discovered a total of 3284. as for Earth-like planets, and possibly habitable, their number goes with a leap, from 12 to 21. one day then for astrophysics, but basically for all of us: to find a our sister is indeed a dream that we harbor since ancient Greece, passing through many philosophers as the unfortunate Giordano Bruno and even poets, as our great poet Giacomo Leopardi, who was a lover of the sky so much to write, work as before adolescence, just a history of astronomy, for the ugly truth.
If all this is correct, however, it is necessary to make some clarifications. First of all Kepler he does not see the planets that discovers, but senses the presence in various ways. The most widely used is to observe some very small changes in light around the star that the satellite is observing, if the planet is indeed among us and this star, as did Mercury cha just two days ago, when he passes in front of its light he is slightly altered. We are talking about less than 1%, and if we want to make an earthly comparison think of a lamppost, perhaps on a promenade in the evening, where we see a small oscillating light due, for example. a moth that spins around and do not see, but of which we can sense the presence after eliminating every other reasonable hypothesis. The planet we do not see, but with very very accurate measurements we can rule out all other causes and also to understand some fundamental characteristics, such as whether it is a rocky planet like Earth, Mars, Venus and Mercury, or gaseous like Jupiter, Saturn and Uranus. We can then understand how great, although with considerable uncertainty and, as in this case, come to the conclusion that it is very likely to rocky planets and with a mass from 1 to 2 times the mass of the Earth.
Again, be careful, because with a mass about twice the Earth a person of 50 kg should weigh at least twice on the 100, then habitable yes but only to a certain extent at least by us. Here we enter the “life” discourse that are declared habitable depends on their distance from the parent star, the planet must be in the Goldilocks conditions, you refer to “Curls of” gold a famous fairy tale that tells its story in Italian small , the planet must not be so close to the star to be on fire, remember the case of Mercury, the closest to the Sun, which reaches temperatures of hundreds of degrees. It must indeed be so far from being a substantially icy world, remember that Pluto goes to 200 degrees below zero and above. This is the minimum course, Mars is in these conditions, but there is life just do not think, maybe there was, we’ll see.
A final issue that must be addressed and that so huge increases our ability to find, before or after a twin of our Earth, is that the valuable Kepler satellite is actually in fact looking around our house, its ability to measure stop to star very close to us. And here we come we Europeans, with Plato satellite under construction and the optical design, the 32 small telescopes that comprise it, are a brilliant Italian idea. He will see more and more distant.
We are now probing a few thousand stars close to our Sun, but just to give a number that makes your head spin, our galaxy has at least 200 billion stars and is only a between 100 billion galaxies in the sky today we count with automatic telescopes. It can therefore in good faith and with high probability to say that a twin of the Earth, or even many, there are somewhere and sooner or later we’ll find them. Perhaps we will never make contact with ETs from somewhere in the cosmos, still they are made, because the cosmic distances exceed the lifetime of a civilization much.
We’re talking about millions or billions of years, and just think that we as Homo sapiens, we are on Earth from 40 to 50 thousand years and probably we are doing everything possible to disappear soon. We hope that our neighbors will behave better than us and that if one day they get are not, as claimed by Stephen Hawking, perhaps the bad guys and use it as a food. But these are bizarre ideas of a very bizarre astrophysicist, although brilliant.
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