Another Earth: Why Exoplanet Proxima B Could Support Alien Life
Astronomers are now trying to determine if the rocky planet orbiting a neighboring star of our solar system could potentially support alien life. Recently, a new study revealed that the rocky planet, dubbed as Proxima B, is likely to be an ocean planet just like Earth.
The study, published in the Astrophysical Journal Letters, found evidence suggesting that an ocean could be covering the entire surface of the planet similar to some icy moons of Jupiter and Saturn. However, the oceans are not the only reason why the exoplanet is being considered to be a good place to search for alien life.
Proxima B is about 1.3 times more massive than Earth. The distance between Proxima B and its host star Proxima Centauri is about 4.6 million miles, or about the tenth the distance of Mercury from the Sun. Despite being near to its host star, Proxima B is not hot enough to prevent water to exist in liquid form.
Proxima Centauri is smaller and 1,000 times weaker than the Sun, making the relatively close distance between Proxima B and Proxima Centauri to be well within the habitable zone.
"Contrary to what one might expect, such proximity does not necessarily mean that Proxima b's surface is too hot" for water to exist in liquid form," study authors said in a statement. "The planet may very well host liquid water on its surface, and therefore also some forms of life."
Using simulations, the researchers estimated the radius of Proxima B to be between 0.94 and 1.4 times that of Earth, which is 6,371 kilometers on average. If Proxima B has minimum radius of 5,990 km and if surface water is present, the researchers estimated that the surface water will take up about 0.05 percent of the planet's total mass.
On the other hand, if the exoplanet has the radius of 8,920 km, the planet's mass would be split 50-50 between a rocky center and surrounding water, with a single 200 km deep ocean surrounding the planet.