Our Closest Earthlike Planet's surface is "Covered" In Water

Astronomers discovered an Earthlike exo-planet revolving around Proxima Centauri, a red dwarf star in our neighboring star system, Alpha Centauri. Known as, the planet is just 4.25 light-years away from our solar system, and there were initial signs that it has rocky surface just like Earth, Proxima b is at the right distance from its star to contain liquid water. Now astronomers and scientists have found a sign that it could actually be "covered" by oceans of water.

Updated version of the previous article.

Just to put in view how cool the finding of Proxima b was before we discovered evidence of its Earth-like merits, the closest known, possibly habitable exo-planet was Wolf 1061c, and it’s 14 light-years far away. That’s 126 trillion kilometers from Earth. Proxima b has since moved that goalpost to just 4.25 light years away, which is almost 40 trillion km or 271,000 times the distance from planet Earth to the Sun, but there’s already an idea in place to get spaceship there in 20 years. To put it another manner, this thing is so near to us, we can, in fact, see two stars in its star system, Alpha Centauri A, and Alpha Centauri B, in the night. Actually, Alpha Centauri A is the fourth brightest star which can be seen from Earth.

Electrifying, right?

Now a team led by scientists at the Marseille Astrophysics Laboratory (MAL) in France has supported the case of Proxima b’s habitability by manipulating a number of size and external properties in additional detail than ever. The image those properties paint is a planet enclosed in liquid water oceans that could possibly sustain life.

The team explains, "The planet could be an 'ocean planet', with a liquid ocean covering its whole surface, and same water to some freezing moons around Jupiter or Saturn."

One of the biggest uncertainties researchers have had about Proxima b’s habitability is the information that it orbits comparatively close to its star, Proxima Centauri. It’s expected to orbit this star at a distance of almost 7.4 million kilometers (4.6 million miles), which is the tenth of the distance that the closest world to our Sun, Mercury, finishes its rotations. With highs of 427 Celsius, 801 Fahrenheit, and lows of -173 Celsius, -279 Fahrenheit, Mercury is not precisely the kind of place you are going to be searching for life, specifically if you are hopeful for liquid water. The worthy news is that the Proxima Centauri star is unlike enough to our Sun to put forward that things might not be so severe on Proxima b, but until recently, some researchers still were not convinced that circumstances would be right for water. Planets that orbit comparatively close to their sun have a tendency to become tidally locked, which means they keep the same face toward their star.

As Emspak highlights, researchers have agreed to the concept that tidally locked planets could possibly be habitable in recent years, but it's been proposed that ‘Proxima b’ might still be too hot to contain liquid water.

To examine this, the French team made simulations of the planet's arrangement based on its actual size and predicted that the radius of the planet is between 0.94 and 1.4 times that of Earth. If we take that lowermost limit, its radius would be approximately 5,990 kilometers, and the team's simulations recommended that in this situation, the planet would be very thick, and contain a metal core that holds two-thirds of its total mass. That core would be bounded by a rocky layer.

The AFP reports, "If there is apparent water, it would not add more than 0.05% to the planet's entire mass, the team said, similar to Earth, where it is approximately 0.02%."

In its place, if we consider the highest radius limit into the simulations, the planet would have a determined radius of 8,920 kilometers, and Proxima b's mass would be divided 50-50 between a rocky center and near water.

Scientists told the AFP "In this situation, Proxima b would be covered by only, Liquid Ocean 200 kilometers deep".

Both simulations recommend that the planet would have a tiny, gassy atmosphere, something that's critical for sustaining life as we believe, and temperatures would not increase above what's equitable for liquid water to exist on its exterior, regardless of being so close to its star.

The team said in a report, "Opposing to what one might imagine, such closeness does not essentially mean that Proxima b's surface is too hot for water to be in liquid form."

Obviously, these are still just accomplished guesses, and we will certainly never know what Proxima b's deal is until we actually get some apparatus out there to measure these effects. By chance, there's even now a mission being funded by Russian billionaire Yuri Milner, known as ‘Breakthrough Starshot’, which expects to laser-propel 'Nano-craft' in the direction of Proxima Centauri, sometime in the next 20 years.

And NASA’s James Webb Space Telescope, planned to launch in 2018, could provide us some ideas about Proxima b's atmosphere by only sampling the star system’s light. Let's just hope that when we do get some more strong measurements, Proxima b turns out looking just as capable as it does at the moment.

The French team's study has been accepted for publication in future publication of The Astrophysical Journal Letters (AJLs), but you can read it online at the preprint website, arXiv.org.