A satellite developed by MIT that looks for dips in brightness as planets cross in front of stars has found three more worlds, the university said.
NASA’s Transiting Exoplanet Survey Satellite found the planets orbiting a star 73 light years away. The planetary system has been dubbed TOI-270, for the 270th “TESS Object of Interest.”
The discovery was detailed Monday in the journal Nature Astronomy.
TESS has found 27 exoplanets, or planets outside our solar system, and is expected to eventually find thousands. It has been in operation for a year, NASA says.
“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 Massachusetts Institute of Technology, said in a NASA statement.
The three planets in TOI-270 are a small, rocky super-Earth and two planets that are about half the size of Neptune.
Scientists were initially excited about the discovery of the sub-Neptune farthest from the star because they thought it might be in a “temperate zone,” where temperatures were right to support life, but they later determined that the planet’s atmosphere is probably a heat trap that would render the planet’s surface too hot for life, MIT said in a statement.
MIT said the three planets are relatively close in size, in contrast to our own solar system, which includes small, rocky worlds, such as Mercury, Venus, Earth, and Mars; the more massive Jupiter and Saturn; and the ice giants of Neptune and Uranus.
The newly discovered sub-Neptunes may be a “missing link” in planetary formation that could help researchers figure out whether small, rocky planets like Earth and massive icy worlds like Neptune form in the same way or differently, MIT said.
Maximilian Günther, a postdoctoral researcher in MIT’s Kavli Institute for Astrophysics and Space Research and lead author of the study, said in the statement there is a good possibility that the system includes other planets farther out that could be within a habitable zone.
The researchers plan further study, including with the upcoming James Webb Space Telescope, to look at the three planets and search for additional planets in a habitable zone, MIT said. The host star is well-suited because it is bright and unusually quiet.
“TOI-270 is a true Disneyland for exoplanet science, and one of the prime systems TESS was set out to discover,” Günther said. “It is an exceptional laboratory for not one, but many reasons — it really ticks all the boxes.”
TESS is a NASA Astrophysics Explorer mission led and operated by MIT and managed by NASA’s Goddard Space Flight Center in Greenbelt, Md. Additional partners include Northrop Grumman, NASA’s Ames Research Center, the Harvard-Smithsonian Center for Astrophysics, MIT’s Lincoln Laboratory, and the Space Telescope Science Institute. Participants include more than a dozen universities, research institutes, and observatories worldwide, NASA said.