The three exoplanets whose existence was unveiled Monday night are not “potentially habitable”. The least it is too early order to say such an assertion. Far too early! If extraterrestrial life exists, there or elsewhere, we have never been as close to discover … just because we seek! At the risk of playing the kill-joys, that’s about all we can say, in the state of knowledge of these three planets of comparable size to the Earth.
The comparison also likely to stop there. Calm down immediately the excitement caused by the announcement in the French press. The Nature paper (visible free here) full of information much less affirmative than most articles published following the release from the European Southern Observatory (ESO) and the University of Liège citing “exoplanets similar to the Earth.” “It seems that the press releases have shown themselves much less cautious than the researchers are,” says rightly Le Monde.
A ” dwarf ultra-cold “as the Sun
What do we really know of Trappist-1b-1c and Trappist Trappist-1d? They revolve around their star, located 40 light years from us in the constellation of Aquarius. This star, Trappist-1, also known as 2MASS J23062928-0502285 is an “ultra-cool dwarf” much bigger than Jupiter. His nickname comes from the small telescope TRAPPIST (for Transiting Planets and PlanetesImals Small Telescope), 60 cm, managed by the University of Liège and based at the La Silla Observatory ESO in Chile.
For amateur astronomers, the star Trappist-1 is too small to be visible to the naked. But now look in red circle, where you could find with the help of telescopes in the constellation of Aquarius
ESO / IAU / Sky & amp;. Telescope
This distant star “is small (& lt; 12% that of the Sun) and its surface temperature is 2500 ° C,” explains Michael Gillon, University of Liege in Belgium, author main discovery published in Nature . Trappist-1 is 2,000 times less bright than the Sun, also believes the journal Sky and Space. and this is a chance.
to detect an exoplanet returns indeed to see the shadow that betrays its passage between its star and Earth. depending on the shade and frequency, scientists calculate its orbit, its distance from its star and its diameter, approximately. If the star emits too much light, exoplanets are embedded in the halo. That is why we find most of the large size of Jupiter that of the smaller size of the Earth.
Two of the three planets are too close to their star
The trio of Trappist-1 system represents a rarity in itself. In terms of their “spaciousness”, there are still many unknowns to be lifted. How close are they to their stars, what temperature is it that, what mass and what density of any composition, there he has an atmosphere, how much radiation suffer-they, a magnetic field the t protects -it etc? Many questions remain unanswered, although it is unclear at this stage whether these planets are rocky or gaseous.
But scientists have however been approximately establish their distance from the star Trappist-1. Result: only the farthest from the “dwarf ultra-cold”, Trappist-1d, remains a potential candidate for the occurrence of (hypothetical) life. The other two planets, and Trappist Trappist-1b-1c, are not found in the “zone of gold loop”. Of zone neither too close nor too far from the star, where it is neither too hot nor too cold, where the radiation level is consistent with the presence of liquid water and the origin of life …
1.1% and 1.5% of the Earth-Sun distance, below the “Goldilocks zone” (as Mercury and Venus in our solar system), they receive two to four times more radiation to their star than the Earth from the sun. But they always present the same face to their star, much like the moon when it revolves around the Earth. This orbit “blocked” allows them to have a face, dark, where the temperature is cooler. Could we find a “growing habitability ‘at the junction between the oven and the freezer?
The “best place to hunt alien life”
As for Trappist-1d, “we have seen that go twice” explains Michaël Gillon Sky and Space . Too little to ascertain its distance from its star and its orbit. It remains eleven possible orbits, according to data scientists who believe that its radiation is significantly weaker than on Earth. “It is possible that it is in the habitable zone.” Possible, not certain.
This discovery remains nonetheless an encouraging first. These three sisters are “conducive to detailed atmospheric studies with current technology,” adds Michaël Gillon. They represent a unique laboratory to detect any ‘bio-signatures “telescope reach. The article in Nature suggests a possible use of Hubble and the James Webb Space Telescope for NASA to refine the meager knowledge of Trappist-1 system. A quartet that already represents the “best place to hunt for extraterrestrial life,” says Gizmodo. Not necessarily to find it.
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