NASA’s world-hunting satellite, the Transiting Exoplanet Survey Satellite, or TESS, has found three of the smallest, nearest planets outside of Earth’s solar system.
One of the planets is rocky and slightly larger than Earth, and the other two are gaseous and roughly double Earth’s size, according to a study published Monday in the journal Nature Astronomy that details the discovery.
The rocky planet, which is 73 light years away, is in what researchers call the “habitable zone,” which means it is far enough from a neighboring star to be able to host water. It also doesn’t have much flare activity, making it easier for scientists to observe.
Photos: Space Over Time
“We’ve found very few planets like this in the habitable zone, and many fewer around a quiet star, so this is rare,” Stephen Kane, a University of California, Riverside associate professor who worked on the study, said in a statement. “We don’t have a planet quite like this in our solar system.”
Still, researchers say it is unlikely that the rocky planet hosts any life because it probably has a thick atmosphere that traps heat and could make its surface too hot to support life. Researchers plan to continue studying the system when the James Webb Space Telescope launches next year.
TESS uses four large cameras to watch sections of the sky for 27 days at a time. It is focused on stars closer than 200 light years from Earth’s solar system.
The satellite recently completed its first year on the job, during which it discovered more than 20 planets outside Earth’s solar system.
“The pace and productivity of TESS in its first year of operations has far exceeded our most optimistic hopes for the mission,” George Ricker, TESS’s principal investigator at the Massachusetts Institute of Technology in Cambridge, said in a press release. “In addition to finding a diverse set of exoplanets, TESS has discovered a treasure trove of astrophysical phenomena, including thousands of violently variable stellar objects.”