Wednesday, June 26, 2013

Habitable planets, really? - Science and Life

Artist's impression of the system Gliese 667C Astronomers have discovered , announce concert band and the European Southern Observatory, the Keck Observatory and the University of Washington, not one, not two, but three planets “living” close to here, in the constellation of Scorpio! Throw on an astronomical scale, of course, 23 light-years, or about two hundred and ten thousand billion kilometers … Habitable? Yes, these three stars would be in the now famous and famous “zone of habitability” of their star, Gliese 667C here, understand at a distance that allows th e water to remain liquid on the surface. Water, life, etc., etc. … Of course, the team Guillem Anglada-Escude, Mikko Tuomi, Enrico Gerlach, Rory Barnes, Rene Heller, James S. Jenkins, Sebastian Wende, Steven S. Vogt, R. Paul Butler, Ansgar Reiners and Hugh R. A. Jones does not explicitly announce that life forms were observed with a telescope on these three new worlds, to meet in the name of Gliese 667C c, f Gliese 667C and 667C Gliese e, but in any case the ad – which follows a string of press releases habitable planets across the galaxy – is indeed written for us to fantasize …
Dreaming possible , and all the more easily that nobody in the coming decades, will not refute that these planets are – or not – of living … For the record, that the question of the habitability of the planet Mars is placed for four centuries, and that to this day, after forty years of in situ exploration of the red planet, nobody eve n gets to decide the question! So planets located a million times farther than Mars?
Search for exoplanets, which made tremendous progress over the last decade, is not example of “hiccups” sounding more or less like this planet ” space “, Gliese 581 g, which probably does not exist, or” the planets “land discovered by the Kepler satellite, which proved to use twice as massive qu’annoncées. In the case of planets Gliese 667C, caution should finally should prevail …
Gliese 667C is a red dwarf star belonging to a triple star system, located so, in the constellation of Scorpio. This red dwarf is three times less massive than the Sun and a hundred times less bright than he. According to the researchers, this star is accompanied by seven planets … This system is staying? The issue is taken so seriously by some researchers that the SETI Institute (Search for Extraterrestrial Intelligences) even pointed a radio teles cope at Hat Creek to catch the potential issuance of one (two, three?) Civilizations to possibly on ! one of these worlds, alas, in vain so far
Let, seriously in reality, these stars ‘habitable’ are only virtual points on curves n … They have not been directly observed or photographed by astronomers with their telescopes, their existence has only been shown via the gravitational perturbation they exert on their stars … From these sinusoids, astronomers have deduced periods, mass, diameter, density … only missing raccoons. In fact, in reality, extracted by the Harps spectrograph of the 3.6 m telescope at La Silla in diameter signal, Chile, is so tenuous and difficult to extract the electronic noise – that the researchers highlight via a statistical calculation. Result, they readily admit that at least one of the seven planets might not exist … The reality of other objects orbiting the star is more or less ques tionable, but in any case their characteristics could still change after new analyzes or observations.
But if these planets do exist , and if, as assumed by the researchers, they are “terrestrial” type they are habitable or inhabited ? Obviously, nobody knows anything, firstly because no one has ever observed the planets such as Gliese 667C: they have absolutely nothing earthly, their mass is understood, according to the calculations of researchers, between two and eight Earth masses! Are they rock, soft, are they covered with water? Impossible to answer this question, of course, because once again, the existence of these stars has been inferred that their gravitational influence on the star!
But, if these planets , appear such as astronomers think, then, are they living, anyway? Very clever that could answer this question, we do know that in the universe inhabited planet and nobody knows how life appeared … Compared to the Earth, the planets of Gliese 667C seem exotic … one example: these planets orbit so close to their stars that turn to it always the same face … In other words, one side of the planet “space” is the perpetual day and a temperature of several hundred degrees. On the other hand, perpetual night, and a temperature of -200 ° C … At the border of these two radically different hemispheres, a twilight zone, the terminator, where probably exchange their extreme temperatures as high winds . Briefly, worlds, or near or far, no mention of terrestrial conditions. Living? Really? Earth has received over four billion years of extraordinarily favorable conditions for seeing life evolve on its surface – a star in the steady radiance, a moon to stabilize its orbit – around Gliese 667C, nothing like: red dwarfs are subject to eruptions of incredible energy – it’s like suddenly the sun became ten times brighter and we bombed ultraviolet and X-ray … In short, anything that we know on Earth or even the system Solar is deployable in a system such as that of Gliese 667C … The planets of this system are invisible, their actual characteristics are unknown, no one knows if they are or not provided with an atmosphere … The exploration of other worlds of the universe, initiated in 1992 with the discovery of the first extrasolar planet Aleksander Wolszcszan and Dale Frail is extraordinarily interesting and rewarding in itself, why researchers feel compelled to punctuate each of their press release regarding the discovery of another world – 900 to the end of June 2013 – the word “space”

? Serge Brunier,

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