Proxima Centauri b is likely to have a habitable ocean
A group of French researchers led by Bastien Bruges from the University of Marseille reported that the planet Proxima Centauri b, recently discovered in the nearest star system, may be covered by a habitable ocean of liquid water. Until now, experts argue whether this planet, similar to Earth in many ways, can be habitable.
The fact that in the neighboring star system Alpha Centauri, located only 4 light years from us, there is an "Earth double", was announced in August 2016. This planet is orbiting the red dwarf Proxima, which is part of the star system along with the brighter α Centauri A and α Centauri B. The mass of the discovered planet called Proxima Centauri b, or simply Proxima b, is only 1.2 times that of Earth. In this case, the celestial body rotates at a small distance from its star, which is why a day on it lasts less than 12 "earthly" days.
Theoretically, the planet is in the so-called "habitable zone" - this means that the temperature on it should imply the possibility of the existence of liquid water. At the same time, the fact that the planet is very close to its star may imply that flares on it can “blow off” water from it, in fact making the planet unusable for life.
To understand what the chances are that Proxima b is potentially habitable, scientists tried to calculate its radius. As it turned out, it is in the range from 0.9 to 1.4 of the Earth's radius. In case the first figure corresponds to the truth, the planet is the so-called supermassive Mercury - a dense planet with a metal core. However, if the second figure is closer to the truth, it means that the planet, like the Earth, is a “layer cake” of a rocky core, an ocean of liquid water on the surface and a relatively thin atmosphere. This structure makes the planet potentially habitable. To test their conclusions, the specialists plan to wait until the radius of Proxima b is measured with higher accuracy.
Scientists sent their research for publication in the scientific journal Astrophysical Journal Letters.
More recently, experts have reported on the possible discovery of another potentially habitable ocean much closer to our planet - it is assumed that it is located deep under the icy surface of Dione, the moon of Saturn. Earlier it was known about five other subglacial oceans in the solar system: two on the other moons of Saturn - Titan and Enceladus - and three on Jupiter's moons Europa, Ganymede and Callisto.
Dmitry Erusalimsky
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