Scientists have claimed the discovery of an Earth-sized planet orbiting the star nearest to our Sun, opening up the gleaming prospect of a habitable world that may one day be explored further.
Proxima b, as it is called, is the planet in a “temperate” zone compatible with the presence of liquid water, the most important ingredient for the presence of any kind of life.
The findings, based on data collected over 16 years, were reported in the peer-reviewed journal Nature.
The planet Proxima b was discovered by astronomers who were looking for the tiny gravitational tug exerted by a planet on its star, after spotting hints of such disruption in 2013.
Proxima Centauri is 4.25 light years from our Earth, making it slightly closer than the binary star system of Alpha Centauri, which the Proxima star loosely orbits around.
“We’ve been excited for a long time,” says Guillem Anglada-Escudé of Queen Mary University of London, who led the discovery as part of a project called Pale Red Dot.
“We’ve been hunting for this signal and confirmation of the planet for almost four years” he added.
“We have finally succeeded in showing that a small-mass planet, most likely rocky, is orbiting the star closest to our solar system,” said Julien Morin, another astrophysicist at the University of Montpellier in southern France.
“Proxima b would probably be the first exo planet visited after a probe made by humans,” Morin shared.
Informally designated Proxima b, the planet revolves around its star once every 11.2 days and is located at a distance of nearly 7 million kms from its star, which is only about 5 per cent the distance between Earth-Sun. The mass of the planet is believed to be about 1.3 times that of the Earth. It could contain water and it is estimated that surface temperatures could be close to – 40 degrees C.
Taking all these factors into account, it is possible that Proxima b can support life or is habitable.
Noticeably, the first exoplanets were spotted in 1995, and today there are over 3,000 known exoplanets. Yet this system is special for being close and lending itself to easy observation.
The astronomers used the HARPS spectrograph to observe it on the European Southern Observatory’s 3.6-metre telescope at La Silla in Chile and also other telescopes around the world. These observations which took place in the first half of 2016 have been dubbed the Pale Red Dot campaign.