SPACE Living conditions on the new exoplanet “potentially habitable” are far from ideal for man …
Know it exists, it’s great. But to move there, better not count on it right away.
The discovery of Proxima B, the planet closest to the Earth apart from those of the solar system, is certainly encouraging.
& gt; & gt; Read also: Exoplanets: “A proof of alien life within ten years”
In a similar mass to our pebble (30% more anyway, according to its co-discoverers) the newcomer is likely to have a floor, a real, not like the soft Jupiter, Saturn, Uranus and Neptune
Another strong point. Proxima B is in a relative comfort zone screw -a-vis its star, to 7.3 million kilometers, when the presence of life seems possible, according to the researchers, between 6.3 and 12.2 million.
for the rest is still a little adventure.
Proxima B was nice to find 20 times closer to its star than we are vis-a-vis the sun, it is not provided Coast d’Azur. Proxima Centauri, the star is a red dwarf whose surface is half as hot (2800 ° C) than that of our sun. Consequently, researchers evaluated at -39 ° C average temperature Proxima B, out of a possible greenhouse induced, for example, water or CO₂.
The hope remains: on Earth, without the greenhouse effect caused by the atmosphere, it would be -18 ° C. Yet he made 34.5 ° C in Lille August 24, 2016
- Atmosphere:. No won
Unfortunately, it is difficult to detect a gaseous envelope to forty trillion kilometers away. Pending the availability of more powerful observational tools, researchers can only indicate the presence of an atmosphere is “not permanently excluded”, despite some discouraging circumstances.
Proxima B is particularly so close to its star (which weighs only 12% of the weight of the Sun) that the atmosphere could be “eroded” by the radiation and magnetic storms Proxima Centauri. In addition, there is a significant chance that the planet has only one face to its star, blocked as the Moon is, vis-à-vis the Earth. This would require heavy traffic to the atmosphere stabilizes, the researchers note
- Living. Irradiated rather than radiant
Free radiograph every time. Red dwarfs like Proxima Centauri are, according to astrophysicist Michaël Gillon, “very active and have a very strong magnetic field.”
According to the researchers who discovered Proxima B, the planet and receive the equivalent of 600 times the magnetic flux sent by the Sun to the Earth, and 400 times the radiation X. prohibitive for growing potatoes? “You never know, it is possible that life forms adapt to radiation,” cautions Michaël Gillon. In addition, the activity of red dwarfs decreases with time: Proxima Centauri may have already reached the age of reason
- Travel. In a very long time
To browse the forty thousand billion kilometers separating us from Proxima B should be, said Michaël Gillon, 50,000 years aboard a spacecraft equipped with current technology. Even at the speed of a space probe as Helios, the fastest object ever built by man (70 km / s), it would still 18,000 years. Only reasonable hope for astrophysicist, “Mastering nuclear fusion,” a technology that would achieve the 30,000 km / s and approach Proxima B forties
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