Only 4.2 light-years from Earth, an exoplanet orbiting in its habitable zone may contain a vast ocean that increases the likelihood that it may support life.
There have been questions about Proxima b’s surface ever since it was discovered; the planet is around 1.3 times as massive as Earth and circles a red dwarf star that is about the same age as the sun.
Studies conducted recently, however, have both raised and lowered expectations for its habitability. A recent study suggests that Proxima b could host life, suggesting that under the right circumstances, the exoplanet could survive liquid water.
Updated version of the previous article.
“The major message from our simulations is that there’s a decent chance that the planet would be habitable,” Anthony Del Genio, a planetary scientist at the N.A.S.A Goddard Institute for Space Studies, told LiveScience.
The researchers conducted what are thought to be the first climate simulations of Proxima b with a dynamic ocean in the study, which was published this month in the journal Astrobiology. The planet is thought to be tidally locked with its star, Proxima Centauri, which means it has a constant ‘dayside’ and ‘nightside.’
While any water on the side left in the dark would be frozen, the opposite side would not necessarily be the case.
“Climate models with static oceans suggest that Proxima b could harbor a small dayside surface ocean despite its weak instellation,” the researchers explain in the new study. “With a dynamic (moving) ocean considered for the first time, the extent of this liquid water becomes much more significant, in some cases even dipping into parts of the nightside. The simulations showed that ‘with a dynamic ocean, a hypothetical ocean-covered Proxima Centauri b with an atmosphere similar to modern Earth’s can have a habitable climate with a broad region of open ocean, extending to the nightside at low latitudes.”
The researchers considered varied salinity levels as well as atmospheric greenhouse gas concentrations, all of which could influence the size of the watery zones. The study discovered that the exoplanet almost always had some kind of liquid ocean in more than a dozen simulations. But don’t get too thrilled about taking a dive just yet.
“We find that an ocean-covered Proxima b could have a much broader area of surface liquid water but at much colder temperatures than previously suggested, due to ocean heat transport and/or depression of the freezing point by salinity,” the researchers wrote.
Soucre: blog.thespaceacademy.org
