Scientists at NASA have discovered that a planet located near the star Proxima Centuri might be capable of harboring life and even of having vast oceans. Earlier studies had determined the planet, called Proxima B, to be uninhabitable.
Proxima Centuri is an M-type red dwarf star that is known to be far cooler than our sun. As such, the planet, located 4.2 light years away from Earth, had to be positioned very close to the star in order to have a chance of sustaining life. However, the problem is that red dwarf stars are known to be highly active.
In their early life, these stars tend to be very hot and bright. This would mean that Proxima B, even if it started out as habitable, would eventually get too hot to harbor any life. Powerful flare activity was also observed from the star, which points to the possibility that the atmosphere of Proxima B could have been stripped away.
However, a new study by NASA states that the planet still has the potential of being habitable. The study theorizes that Proxima B initially formed far away from the star and eventually moved closer to it. This would have let the planet escape the extremely hot temperatures of the dwarf star during its early phase.
The report also puts forward the possibility that the distant planet might have contained 10 times more water than Earth. As such, even if any radiation blast would have stripped away most of its water, the planet could still have enough liquid to sustain life.
The team also used custom software to ascertain the type of atmosphere and liquid content that the planet might have. The results came out very positive, indicating the presence of vast oceans.
“So if it has an atmosphere and has water, Prox b has a pretty good chance to be habitable. We also found that the ocean currents carried warm water from the dayside to the nightside, keeping parts of the nightside habitable even though they never see any light. And if the ocean is very salty, almost the entire planet could be covered by liquid, but with temperatures below the usual freezing point almost everywhere,” Universe Today quotes Anthony D. Del Genio, leader of the research group.
The study also points to a possibility that other rocky planets that orbit M-type red dwarf stars might also be habitable. And considering that these stars form about 70 percent of all known stars in the Milky Way, the chances of discovering a habitable planet have vastly increased.
Other habitable planets
In addition to Proxima B, several other planets have been identified by scientists as having the potential for sustaining life. The most interesting among them is a planet named Wolf 1061c from the Ophiuchus constellation.
Located about 13.8 light years away from our planet, Wolf 1061c is reportedly the next potentially habitable planet known to scientists after Proxima B. The planet has an estimated mass that is 4.3 times that of the Earth and takes 17.9 days to complete an orbit around its star.
Other nearby planets that look promising for scientists include Gliese 832c, Gliese 667Cc, and TRAPPIST-1d. These are however much farther away from us than Proxima B. As such, this planet still remains our best chance of finding a habitable planet.