BERLIN – An international team of astronomers announced on Wednesday the discovery of a temperate planet, similar in size to Earth, only 11 light years from our Solar system, according to a statement issued by the European Southern Observatory.
The ESO team used their unique planet-hunting High Accuracy Radial Planet Searcher (HARPS) instrument to locate planet Ross 128b.
HARPS is described by the co-leader of this breakthrough, Xavier Bonfils of the Grenoble Institute of Planetology and Astrophysics in France, as “the shortcut to happiness, as it is easier to detect small cool siblings of Earth around these stars than others more similar to the Sun.”
This new exoplanet is the second-closest temperate planet detected after Proxima b, and the closest planet discovered orbiting an inactive red dwarf star, thus increasing the chances the planet may sustain life.
“Although it is currently 11 light-years from Earth, Ross 128 is moving towards us and is expected to become our nearest stellar neighbor in just 79,000 years – a blink of the eye in cosmic terms,” said Bonfils. “Ross 128b will by then take the crown from Proxima b, and become the closest exoplanet to Earth.”
Ross 128 b, therefore, becomes a prime target for ESO’s Extremely Large Telescope located at La Silla Observatory in Chile, to search for telltale biomarkers in the planet’s atmosphere, according to a study published in the latest issue of “Astronomy Astrophysics.”
According to the data currently available, the low mass exoplanet orbits around red dwarf star Ross 128 every 9.9 days and has a surface temperature similar to that of Earth.
Red dwarfs have extremely long life cycles and are a good target to seek exoplanets as they are relatively weak and cold stars, which made them very difficult to detect in the past as they are not very luminous, although in some cases they can emit lethal ultraviolet radiation or X-band flares that bathe any nearby planets making them non-viable for human life.
The good news is that Ross 128 seems to be a quiet, gentler star raising hopes it may be a suitably hospitable environment for life, according to the ESO statement.
“Only HARPS has demonstrated such (astrophysical) precision and it remains the best planet hunter of its kind, 15 years after it began operations,” according to Nicola Astudillo-Defru, of the Geneva Observatory in Switzerland and co-author of the discovery paper.
HARPS data revealed to the ESO team that Ross 128b orbits 20 times closer to its star than Earth does.
Nonetheless, it only gets 1.38 times the radiation on Earth’s surface and surface temperature could range between -60 and 20C (-75F to 68F), thanks to the cool and faint nature of its small red dwarf host star, which has just over half the surface temperature of our Sun.
The ESO astrophysicists have yet to determine whether the planet lies inside, outside, or on the cusp of the Goldilocks habitable zone, where liquid water may exist on a planet’s surface.