“It’s like taking Earth a bit further away, but it’s comparable”, explained Dr Anglada-Escudé. Well, a new study led by some of my colleagues at Queen Mary University of London has finally done just that.
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The newly-discovered planet orbits “Proxima Centauri” – the star closest to the Sun – every 11.2 days, says a report in the magazine ‘Nature’.
Four years ago another group of scientists excited the world with a claim of a planet – not in the habitable zone – around Alpha Centauri, a star a bit farther away.
Scientists say their investigations of the closest star, Proxima Centauri, show it to have an Earth-sized planet orbiting about it. Doppler data lets scientists study tiny movements of a host star, which tend to be the result of the gravitational pull of an orbiting planet. The first signals of a world orbiting Proxima Centauri were recorded more than a decade ago, and more such signals have continued to trickle in – but never enough to be convincing. “The recent Pale Red Dot campaign has been about two years in the planning”.
However, there hasn’t been any detection of an atmosphere on Proxima b or of what gases that atmosphere might consist.
From the data gathered, the team has determined quite a lot about the planet’s properties.
Proxima b is thought to be only 4.7million miles from its star, one-twentieth of the Earth’s distance from the Sun. It is probably in the not-too-hot, not-too-cold Goldilocks Zone where liquid water – a key to life – is possible, if the planet has an atmosphere.
The global team of astronomers that announced the discovery haven’t seen Proxima b but confirmed its existence indirectly using telescopes to identify and precisely calculate the gravitational pull it had on its star, a proven method in exoplanet-hunting.
Social media is beginning to light up with the possibility that Proxima B is the new frontier in the search for life outside of our own.
Similarly, the planet can’t be too small, or it won’t have enough mass to hold onto an atmosphere for long enough for life to emerge. But it does add to the field of exoplanet research that’s underway, some of which hopes to identify Earth-like planets that future telescopes, like the James Webb Space Telescope and the European Extremely Large Telescope, can use for observation.
These might also reveal if any of the ingredients for life are present. But Proxima b may not be quite as hospitable as Earth.
One complication to the analysis is that red dwarfs like Proxima Centauri are active stars, and their natural brightness variations could mimic the presence of a planet. The proximity of Proxima b to the star could also mean that the planet is “tidally locked”, with one side always facing the star in perpetual day and the other in unending darkness.
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The true test would be to go there. It is within what scientists refer to as the “habitable zone” of Proxima Centauri, so there is at least a higher chance that it does. Traveling at 20 percent of the speed of light, a fleet of StarChips would make the trip in only 20 years.
