Before you rocket past LHS 1140b thinking it’s just another exoplanet, especially after the upsurge in excitement over exoplanets in the wake of TRAPPIST-1, scientists believe this one has the highest potential for hosting extraterrestrial life. Ever.
Just 40 light-years away in the constellation of Cetus (aka the Sea Monster) is a super-Earth that was unearthed by ESO’s HARPS (High Accuracy Radial Velocity Planet Searcher) instrument in collaboration with an international range of telescopes. It was the MEarth array that first detected the unmistakable dips in starlight when the alien planet was in transit of its star, dim M-dwarf LHS 1140. Sound familiar? The TRAPPIST-1 system also orbits an M-Dwarf, but here’s why this discovery could be even more explosive.
Follow-up observations by HARPS told astronomers they were looking at a super-Earth, which they estimate to be at least 5 billion years old and slightly larger but significantly more massive than our planet. HARPS also confirmed its higher mass and density, which are indicators of a rocky planet with an iron core. LHS 1140b orbits in the habitable zone of its star, something that may initially flip the “aliens” switch in the minds of both Ph.D.’s and armchair astronomers, though this is just one reason this planet could be, or at least could have been, a potential hotbed for life.
“This is the most exciting exoplanet I’ve seen in the past decade,” said Jason Dittmann of the Harvard-Smithsonian Center for Astrophysics in an ESO science release. “We could hardly hope for a better target to perform one of the biggest quests in science—searching for evidence of life beyond Earth.”
What qualifies as the habitable zone for LHS 1140b is ten times closer to its star than Earth is to the sun, but only half as much light shines on it because its star is so much smaller and cooler. The research team is optimistic that it has retained most of its atmosphere despite bathing in deadly radiation from the red dwarf for billions of years. An atmosphere is mandatory for life (at least as we know it on Earth) to thrive. Liquid water is the other absolute must, which is theorized to have been produced by steam rising from an ancient magma ocean. LHS 1140b’s size has astronomers convinced it could have once been oozing with magma. The steam is thought to have escaped into the atmosphere, where it condensed and fell to the planet as rain.
LHS 1440b has opened a portal to new possibilities for shedding light on planets with the capacity to support life. Observations from Hubble will soon reveal how much high-energy radiation the exoplanet is exposed to, which will further specify how likely it is to be crawling with anything. Future technologies such as the upcoming Extremely Large Telescope and the James Webb Telescope should be able to observe alien atmospheres at a level of detail that will be nothing less than mind-blowing.
"The LHS 1140 system might prove to be an even more important target for the future characterization of planets in the habitable zone than Proxima b or TRAPPIST-1,” predict research team members Xavier Delfosse and Xavier Bonfils. “This has been a remarkable year for exoplanet discoveries!"