For a planet to be favorable to the appearance of life, one of the main requirements -between other geochemical, astrophysical and geophysical parameters- is that its orbit is located in the habitability zone of some energy source, where the temperature allows the existence of liquid water. One of the most promising exoplanets is Next b, which orbits around Proxima Centauri, the closest star to Earth after the Sun. And although at first it was speculated that the radiation had withered its surface, a recent study determined that could contain oceans and be fit for life.
Through mathematical models Similar to those used to analyze climate change on Earth, the researchers determined that Próxima b is able to conserve huge areas of liquid water on its surface, which greatly increases your chances of harboring living organisms. The results of the research were published in Astrobiology.
Next Centauri. It is a small reddish star that belongs to the largest population of stars in the Galaxy: the red dwarfs. Its distance from the Sun is determined precisely by the parallax method: 4.24 light years.
Estimates from the team led by Antony of Genius, NASA's Goddard Institute of Space Studies, pointed out that Proxima b is just enough to receive enough starlight and maintain its surface above the freezing temperature of the water.
This exoplanet is 1.3 times larger than that of Earth and is located in Alpha Centauri, a triple star system at a distance of 4.2 light years. This set of 3 stars includes two bodies similar to the Sun (Alpha Centauri A and B) and a red dwarf called Proxima Centauri.
To reach these conclusions, they were modeled 18 virtual scenarios, taking into account the effects of gigantic continents, extremely thin atmospheres, different atmospheric compositions and even changes in the salinity of the global ocean. And in almost all models, Próxima b ended up having large open and durable seas in at least part of its surface.
The mystery of life. For the work the researchers determined that, hypothetically, Centauri B has an atmosphere and an ocean on its surface, which means that it is just enough distance to receive enough starlight
photo: NASA / JPL-Caltech / NASA / dpa find exoplanets system Trappist astronomy discovery of seven new planets planets system trapista
"The main message of our simulations," Del Genio said to Live Science magazine, "is that there is a more than decent chance that the planet is habitable."
At the end of 2016, a team from Queen Mary University in London, directed by Guillem Anglada-Escudé, had carried out a similar simulation and concluded that the always-lit hemisphere of Proxima Centauri b would be subjected to very high temperatures, while the dark hemisphere would be extremely cold.
What was not contemplated is that the habitable zone of Proxima Centauri is extremely close to the star. Which implies that the exoplanet present tidal coupling. That is, the same side of Proxima Centauri b always is facing its star, as in the case of the Moon, which always shows the same face to Earth.
In this sense, the new tests were more exhaustive since they he contemplated a dynamic and circulating ocean, which could transfer heat from one side of the exoplanet to the other very effectively. In the researchers' findings, the movement of the atmosphere and the ocean combine so that "although the nocturnal side never sees starlight, there is a fringe of liquid water that hangs around the equatorial region," Del Genio said. .
As an example, the researchers compared this circulation of heat to the maritime climates of our own planet. The East Coast of the United States, without going any further, is warmer than it should be because the Gulf Stream carries warm water from the tropics. In California, by contrast, ocean currents bring cold water from the north, so the west coast is colder than it would be without that input.