Read More: New Scientist
A newly discovered planet orbiting a nearby star could be the closest world to Earth that offers a comfortable home for life. The Earth-sized planet, named Ross 128b, is just 11 light years away and thought to have a relatively mild climate with temperatures ranging between an icy -60°C and balmy 20°C. That could mean it has oceans and lakes in which life may have evolved. But the best news for possible life on Ross 128b is the planet’s peaceful parent star. Like many other exoplanets that we’ve found, it orbits close to a dim and cool red dwarf star at a distance 20 times less than that between the sun and Earth. The habitable zone of a red dwarf – the narrow temperature belts where surface water can persist without freezing or boiling away – is usually quite close to the star. Since red dwarfs are prone to deadly eruptions of ultraviolet radiation and X-rays, this can be dangerous. Planets close to most red dwarfs are likely to be severely irradiated, causing many scientists to doubt that life could survive on them regardless of whether they’re in the habitable zone. However, Ross 128b’s star is much less volatile than typical red dwarfs. Even though the planet orbits quite near its star, its surface probably receives only about 1.38 times more radiation than the Earth. Wobbly star motion Conditions on the closest exoplanet to Earth that sits in a habitable zone, Proxima Centauri b, are likely to be far less pleasant. Its star, Proxima Centauri, is also a red dwarf, but it regularly unleashes bursts of radiation and solar wind particles powerful enough to strip the atmosphere from a nearby planet.