New planet may be close enough to spy signs of life
39 light-years away is world similar to ours
Special for USA TODAY
Scientists have found a planet the size of a jumbo Earth circling a nearby star, meaning it is one of a handful of worlds where astronomers’ sensors might be powerful enough to detect signs of life.
The new planet, known as LHS 1140b, receives enough starlight to allow for liquid water, a prerequisite for life on Earth. The planet lies 39 light-years from our solar system — not exactly in the backyard but close enough that telescopes under construction may be able to spot oxygen molecules swarming around it.
“With this discovery, we have a world similar to Earth in some aspects and dissimilar in some others,” says Amaury Triaud of Britain’s University of Cambridge, who was not involved with the research.
The first subtle signs of the planet’s presence were recorded in 2014, but no one noticed until Jason Dittmann, then at the Harvard-Smithsonian Center for Astrophysics, reanalyzed the data. “It turns out it was lurking there all along,” says Dittmann at MIT. To confirm the planet’s existence, Dittmann and his team enlisted three academic telescopes and one operated by a crackerjack amateur in Perth, Australia, who kept vigil when bad weather sidelined the pros.
The joint exercise revealed a small, dim star circled by a small, tubby planet.
Nearly seven times more massive than Earth, it is probably made in good part of rock, the researchers say in a study in this week’s Nature. Such rocky worlds seem a better bet for hosting life than do the puffy gas planets orbiting other stars.
Another point in 1140b’s favor: “Its temperature is very mild and similar to what Earth experiences today,” Dittmann says.
Astronomers have found roughly 20 Earth-size planets that might support liquid water, according to a database maintained by the University of Puerto Rico at Arecibo. Many are so far away that it will be a challenge to get to know them.
“There are better prospects for learning more about this planet than some of the others,” says Eric Ford of Pennsylvania State University, who was not involved in the study.