Proxima b - Closest Planet Found in Habitable Region, it may Support Life! - Sciengit

Alpha Centauri A, Alpha Centauri B with Proxima Centauri in red circle

Alpha Centauri A and Alpha Centauri B. Proxima Centauri is shown in a red circle. Image by Skatebiker at English Wikipedia, CC BY-SA 3.0

Alpha Centauri A and Alpha Centauri B makes up a binary star system which is known to be the closest star system to our Solar System in the constellation of Centaurus is no more than a target for the scientists to reach. It would be the first ever interstellar flight to another system which would be no more but a glory. Proxima Centauri is a red dwarf star that might be attracted by gravitation to this Alpha Centauri system.

Talking about glory, scientists have just discovered Proxima b, a planet revolving around a smaller star of this binary system, just at the right position to sustain liquid water on its surface, and could potentially support life. But the glory that this planet gave to the scientists and the researchers is not only that it is habitable, but also that it is now found to be the closest ever habitable planet away from Earth.

Proxima b and its star, Proxima Centauri. Source: SPACE.com

Discovery of Proxima b

This is what Proxima b could look like!

Proxima b was discovered in Chile by the European Space Observatory on 24th of August 2016. This planet was detected due to the Gravitational Tugging.

Gravitational Tug is the force that a star exerts on its planet.

Doppler Spectroscopy: A planet causing
its parent star to wobble

Planet in return exerts a small tug on its star as well. This Gravitational Tug is technically named as Doppler Spectroscopy. This makes a star to wobble a little which makes it possible for scientists to observe the wobbled light emitted from the star. Due to the difference that this wobbling creates in the color of light which is detected, scientists can work out the on this difference as the time of wobbling to find out how big a planet is revolving around a star, how close it is to its parent star, and how long does that planet takes for a complete revolution. As for the case of Proxima b, it takes 11.2 days of Earth for a complete revolution at a distance of 5% of Astronomical Unit having a mass equal to 1.3 times the mass of Earth.

Astronomical Unit is the distance between Earth and the Sun. 1AU is approximately 150 million kilometers.

There are thousands of candidates found by Kepler Space Observatory that can support life are: Earth sized planets, and rocky planets. But none of them makes it possible for scientists to reach there as they are too far away and it could take thousands of years to reach there with the best speed a man-made machine have reached including Juno and Voyager probes.

Related: Juno becomes the fastest man-made machine

Read about Juno reaches Jupiter

This makes our neighboring stellar system interesting and important to consider; and now with another most fascinating habitable earth-sized exoplanet candidate, Proxima b, it is now even more important to inspect.

But are the scientists so sure about the surface of Proxima b? Is it rocky or is it having all water on its surface? No they are not. However, this exoplanet is revolving a red dwarf star which makes it likely to have a rocky surface as according to the previous researches on exoplanets says that such planets orbiting a significantly smaller star mostly do have a rocky surface.

Is it really 'habitable'?

The two things that scientists do to label a planet as habitable are - its ability to sustain liquid water on its surface and planet having a rocky surface, do not actually mean that the planet is habitable. Life can not potentially exist due to these two reasons only.

The planet should also be tidal free, which means that it rotates along its own axis as well just like our own blue gem, Earth, does. If a planet is tidal locked, only one side of a planet faces the star while the other side faces the darkness of space. This denotes that carbon-cycle needed for the plantation is not going to be happening on either sides, which ultimately makes this planet naturally inhabitable as there is no source of food.

Carbon-cycle. Source: cpalms.org

If somehow humans reach there via some futuristic technology, we will have to grow plants artificially using ultraviolet light. As a result, the plants will be black in color, however, we would be having this food problem get solved. Even if we perform this method successfully, the people living on surface of planet will either face the dark sky and will be having exceedingly cold temperatures all day long as well as making it difficult for plants and bacteria to grow, or humans will just experience the brighter days 24/7. This whole case of tidal locking does not make a planet habitable in any way.

Second thing, which makes a planet habitable is its daily combat with high-energy radiation emission from its star. Our Earth possesses a powerful magnetic field which shields the planet every time from the high-energy radiations from the Sun which make Aurora in sky. If a planet is weaker in this combat, its atmosphere is not going to be retained and will be destroyed in future, just as the destruction of atmosphere of the red planet, Mars.

The real problem begins here as scientists do know that Proxima b lies in the habitable zone and it might be a rocky planet but they are not sure and are currently having no clues to answer the questions raised on its habitability considering all the points made above.

Info-graphics of Proxima b

Brief Information of Proxima b. Source: SPACE.com

We have sure a lot of things to uncover but the reason of all this hype over this planet is just the superior importance Proxima b has over being found as the closest ever exoplanet away from Earth.