At a distance of 4.2 light years from us is Proxima b - the closest potentially inhabited Earth-like planet outside the solar system. A new study of this world indicates that the planet may be completely covered in water. Is it time to pack your bags?
In August this year, scientists from the European Southern Observatory (ESO) confirmed the discovery of a rocky planet in the habitable zone of Proxima Centauri, the closest star to us. Little is known about the planet so far, so it is too early to speak with confidence about the presence of life on it, however, a new study, the results of which were accepted for publication in the scientific journal Astrophysical Journal, indicates that Proxima b may be covered by oceans or even has one giant ocean covering its entire surface.
In general, Proxima b is a very interesting candidate for research. And not only because it is an earth-like planet located in the closest star system to us. Its mass is approximately 1.3 times the mass of the Earth. Its orbit is located about one tenth the distance from Mercury to the Sun. This should not create problems for potential life, since Proxima Centauri, the native star of this planet, is about 1000 times weaker than our Sun. In addition, the planet is in the habitable zone, that is, water on the surface can be kept in a liquid state.
There weren't many observations of Proxima b. Therefore, Bastein Brugger and his colleagues from the University of Marseille conducted a series of computer simulations to better understand its possible composition and radius. The study showed that the radius of Proxima b can be somewhere between 0.94 and 1.4 of the Earth's radius, which averages about 6,300 kilometers.
If the planet's radius is actually closer to the lower bound of the calculations, then, most likely, its composition is very dense, the planet has a metal core, which accounts for two-thirds of the total mass of Proxima b. The core is most likely surrounded by a dense mantle. Any water on the surface of this planet would most likely account for about 0.05 percent of the total mass of the planet (on Earth, this figure is 0.02 percent of the total mass).
However, if the real radius of the planet is closer to the upper limit of the calculations (about 8920 kilometers), then it becomes even more interesting. In this case, the mass of the planet will be divided between its solid center and the surrounding water.
"In this case, Proxima b would most likely have a single liquid ocean about 200 kilometers deep," the scientists comment in the article.
"In both cases, the planet could be surrounded by a thin gaseous atmosphere, like on Earth, making Proxima b potentially habitable."
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Such statements are encouraging, but we need to learn more about this planet before drawing final conclusions. Scientists have created their models taking into account the presence of a thin atmosphere in Proxima b, but we do not know what kind of atmosphere this planet has, or if it has at all.
NIKOLAY KHIZHNYAK