Astronomers report that NASA’s Transiting Exoplanet Survey Satellite, or TESS, has detected its first Earth-sized planet lying in its parent star’s habitable zone, plus its first planet orbiting two stars.
Astronomers are sharing a flood of findings from NASA’s Transiting Exoplanet Survey Satellite, or TESS, including the detection of a potentially habitable super-Earth far beyond our solar system.
The planet is said to circle an M-type dwarf star called GJ 357, about 31 light-years from Earth in the constellation Hydra. Known as GJ 357 d, the world is at least six times more massive than Earth — and orbits the star every 55.7 days, at a distance that’s only 20% as far away as Earth is from our own sun.
With that orbit, GJ 357 d would be broiling-hot if it were in our solar system. But its parent star is so much dimmer than our sun that the super-Earth could conceivably be just warm enough to have liquid water. That characteristic serves as the definition for habitable zones around alien suns.
“This is exciting, as this is humanity’s first nearby super-Earth that could harbor life – uncovered with help from TESS, our small, mighty mission with a huge reach,” astronomer Lisa Kaltenegger, who’s the director of Cornell University’s Carl Sagan Institute, said in a news release.
Less than a year after NASA’s TESS spacecraft was launched, the scientists behind the mission have unveiled their third confirmed planet, a weird alien world that’s between Earth and Neptune in size. And hundreds of additional potential finds are in the pipeline.
The latest exoplanet on the list is HD 21749b, which orbits a star that’s about 80 percent as massive as our sun, located about 53 light-years away in the southern constellation Reticulum. Its 36-day orbital period is a record high for the TESS mission.
The “sub-Neptune” planet is about three times Earth’s size, but 23 times its mass. In comparison, Neptune is almost four times as wide as Earth but only 17 times as massive.
Astronomers on the team for NASA’s Transiting Exoplanet Survey Satellite mission, or TESS, are reporting their first potential planet discoveries, just days after the spacecraft’s first science image was unveiled.
The first reported candidate planet was detected orbiting a star known as Pi Mensae, a sunlike yellow dwarf star nearly 60 light-years from Earth that was already known to harbor a world that’s more than 10 times as massive as Jupiter.
The newly detected prospect is closer to its parent star in the southern constellation Mensa, making a complete orbit every 6.3 Earth days.
In a paper published on the ArXiv pre-print website and submitted to the journal Astronomy & Astrophysics, the team’s scientists say Pi Mensae c appears to be about twice as wide as Earth and 4.5 times as massive.
Its density is estimated as roughly equal to water’s density, which suggests the planet is a super-Earth that “may have held on to a significant atmosphere,” the scientists say.
The second candidate planet orbits a red dwarf star known as LHS 3844, 49 light-years away in the constellation Indus. LHS 3844 b is thought to be a “hot Earth,” with a diameter about a third wider than Earth’s. It swings around its sun every 11 hours.
The first science images from NASA’s Transiting Exoplanet Survey Satellite focus on a strip of southern sky that includes the two nearest dwarf galaxies and plenty of potential targets in the probe’s planet search.
“In a sea of stars brimming with new worlds, TESS is casting a wide net and will haul in a bounty of promising planets for further study,” Paul Hertz, astrophysics division director at NASA Headquarters, said today in a news release. “This ‘first light’ science image shows the capabilities of TESS’ cameras, and shows that the mission will realize its incredible potential in our search for another Earth.”
TESS was launched from Florida in April by a SpaceX Falcon 9 rocket, and the mission team has been spending the past few months getting the spacecraft ready for what’s expected to be a two-year mission.
The newly released imagery was captured by TESS’ four wide-field cameras during a 30-minute session on Aug. 7. The mosaic shows parts of a dozen constellations in the southern hemisphere, from Capricornus to Pictor.
TESS’ image was taken by one of its cameras with a two-second exposure. The picture is centered on the constellation Centaurus, with the edge of the dark Coalsack Nebula at upper right and the star Beta Centauri prominent along the lower edge.
The picture provides only a hint of what TESS will be seeing once it starts delivering science-quality images next month. When all four wide-field cameras are in operation, TESS’ images should cover more than 400 times as much of the sky.
SpaceX has launched NASA’s Transiting Exoplanet Survey Satellite, or TESS, kicking off a mission aimed at surveying nearly the entire sky for exoplanets.
The probe rose into space atop a SpaceX Falcon 9 rocket, sent up from Cape Canaveral Air Force Station in Florida at 6:51 p.m. ET (3:51 p.m. PT) today.
TESS was supposed to take off on April 16, but the launch teams said they wanted more time for guidance, navigation and control analysis. No issues were reported this time around.
Minutes after launch, SpaceX landed the Falcon 9’s first-stage booster on an autonomous drone ship named “Of Course I Still Love You,” hundreds of miles out in the Atlantic. Over the past two years, such landings have become routine.
NASA and SpaceX say they’ll take more time to launch the Transiting Exoplanet Survey System, or TESS, just to make sure the $337 million mission will be on the right track to hunt for planets beyond our solar system.
TESS’ liftoff aboard a SpaceX Falcon 9 rocket had been scheduled for today, but in an online update, NASA said “launch teams are standing down today to conduct additional guidance, navigation and control analysis.”
The launch was retargeted for April 18, with an anticipated liftoff time of 6:51 p.m. ET (3:51 p.m. PT).