ESO/M. Kornmesser

This exoplanet could be a better candidate for life than Proxima b

Proxima b, discovered last year, may be our nearest Earth-sized exoplanet, but it wouldn’t be where you’d want to spend your next space vacation. That’s because its star, Proxima Centauri, regularly blasts the planet with deadly ultraviolet light and x-rays. Now, astronomers have found a potentially more hospitable destination, and not much farther away. Using the European Southern Observatory’s High Accuracy Radial velocity Planet Searcher instrument in Chile, researchers detected a slight wobble in the position of a star called Ross 128, indicative of an orbiting planet. Both Ross 128 (11 light-years from Earth) and Proxima Centauri (4 light-years from Earth) are red dwarfs—the most numerous star type in the galaxy. But Ross 128 seems to be more tranquil, not emitting the flares that would plague life on a nearby planet. As the team describes today in Astronomy & Astrophysics, the planet they found—Ross 128 b—orbits its star in just 9.9 days at 1/20 the distance from Earth to the sun (artist’s rendition, above). The planet, which the team estimates has an average surface temperature between –60°C and 20°C, avoids getting fried because red dwarfs are much dimmer than our own sun. Ross 128 b’s closeness makes it a prime candidate in searches for alien life, but that will have to wait until more sensitive instruments and telescopes come on line in coming years.