A recently discovered planet, broadly considered to be Earthlike in that it has a mass about a third larger than Earth’s and surface temperatures moderate enough to support ground water, orbits our sun’s nearest stellar companion 24.8 trillion miles away, scientists said today.
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“Proxima Centauri b is a potentially habitable world around our closest star – and maybe also a far future travel destination”.
Scientists in the past 20 years have found more than 3,000 planets outside our solar system, or “exoplanets”.
“It’s not only the closest terrestrial planet found, it’s probably the closest planet outside our solar system that will ever be found because there is no star closer to the solar system than this one, and any planet around that star is the closest to our solar system”, said lead study author Guillem Anglada-Escudé. Proxima b is a little more massive than the Earth and orbits in the habitable zone around Proxima Centauri, where the temperature is suitable for liquid water to exist on its surface.
“However, “discussion of life on Proxima is premature”, Dr. Paul Butler, staff scientist at the Department of Terrestrial Magnetism with the Carnegie Institution for Science”, told CDN by e-mail last night.
Since the first exoplanet was discovered in 1995, astronomers have identified more than 3000 such bodies orbiting distant stars. Dr. Endl is a research scientist and lecturer at the Donald Observatory at The University of Texas at Austin. We don’t know how it originates and don’t really have a solid definition of life.
In an independent and upcoming paper, now available online here, Kaltenegger and Carl Sagan Institute research associate Jack O’Malley-James explore how life could survive around a flare star – like Proxima Centauri – and how those flares could actually uncover a hidden biosphere on another world.
The group of researchers, using the European Southern Observatory (ESO) telescopes, have named the exciting world Proxima b. The double star Alpha Centauri AB also appears in the image to the upper-right of Proxima itself. The former scenario would make an atmosphere more likely. High energy particles and radiation nearly always simply pass through single cell creatures.
It is potentially a major step in the quest to find out if life exists elsewhere in the universe. The habitability of a planet like Proxima b is also “a matter of intense debate”, according to the study, due to arguments against it: tidal locking, strong stellar magnetic fields, strong flares, and high ultraviolet and X-ray fluxes.
How fast can we get something to this planet?
However, being tidally locked does no preclude the presence of an atmosphere.
The way Proxima b rotates, strong radiation from its star and the formation history of the planet makes its climate quite different from that of the Earth.
Location in a habitable zone, however, is not the only factor required for sustaining life. In fact, life may be a fringe element in this universe.
Of course, it may be a while before we can have a look-see. Assisted by gravity, the Juno spacecraft to Jupiter attained a top speed of about 160,000 miles per hour, according to a Scientific American blog, the barest fraction of any practical speed for such a distance.
Shadow searching – When a planet passes directly between its star and an observer – an astronomer peering through a telescope, or a satellite in space – it dims the star’s light by a tiny but measurable amount.
Researchers estimate that if the planet has an atmosphere, which could be assumed but isn’t known, it may be between 86 to 104 degrees Fahrenheit on the surface. At that speed, it would take more than 130,000 years to reach Proxima b.
‘The first hints of a possible planet were spotted back in 2013, but the detection was not convincing, ‘ said Dr Anglada-Escudé. However, because the results were indistinct and another three years of refined measurements by a world-wide teams of scientists were needed for a more definitive finding. University of Hertfordshire Prof. Hugh Jones, another of the report’s coauthors, said that initial observations of Proxima b were made more than 15 years ago.
In April, Russian billionaire Yuri Milner and super-famous physicist Stephen Hawking announced they had an idea to send teeny, tiny spaceships to Alpha Centauri, the next closest star after Proxima.
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Its orbit is 7.5 million kilometres from Proxima Centauri, just five per cent of the distance between Earth and our own Sun.
