A planet around 1.3 times as massive as Earth has been detected orbiting the closest star to the sun: Proxima Centauri, a dim red orb some 4.25 light-years away in the southern constellation Centaurus. The star is a red dwarf, about one-seventh the diameter of that of the Sun.
The new world has been called Proxima b, as reported in the journal Nature — “A terrestrial planet candidate in a temperate orbit around Proxima Centauri.” It is very close to the star, needing just 11.2 days to complete one orbit. However, because the star is much smaller and less ‘powerful’ than our Sun, the newly detected planet could have some similarities to Earth. The word ‘detected’ is also important, for astronomers have not observed the planet directly; instead they have detected it from its influence on its star, using instruments at the European Southern Observatory in Chile. The star, in effect, wobbles when the planet moves around it. In time, the European Extremely Large Telescope, which is currently under construction, it might be possible to capture a direct image of the planet.
The new planet is of interest because of its proximity to Earth and the outside chance that it might be habitable. Early news reports that the planet it habitable are incorrect; the planet is close enough to its star that it falls within the habitable zone — which is not the same thing as the planet being life-supporting. Instead, what this means is that if water is present on the planet, it could be in liquid form.
Moreover, it is not known whether the planet contains water, is rocky or has an atmosphere. There have been hundreds of other exoplanets (a planet that orbits a star other than the Sun) discovered, many via the Kepler space observatory, that are more likely candidates for being habitable. These worlds (just as difficult to communicate with let alone reach) offer a greater prospect of being life-supporting or perhaps even containing a life-form.
