An alien Earth that just might be habitable has been discovered in years-old records, thanks to sharp-eyed astronomers who gave the data a second look.
Tag: Exoplanets
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.
Over the past 42 years, filmgoers have seen exotic worlds come to life in a succession of Star Wars movies — a series that is now coming to a climax with “Star Wars: Episode IX, The Rise of Skywalker.” But are those exoplanets really all that exotic anymore?
Sure, we’ve seen two suns in the sky over the sands of Tatooine, Luke Skywalker’s home planet. We’ve been to an ice planet (Hoth) and a lava planet (Mustafar). We’ve even spent time on a habitable exomoon that’s in orbit around a gas giant (Endor).
Back in 1977, most of us might have thought those types of worlds to be science-fiction fantastical. Today, they’re seen as totally plausible categories in the study of thousands of planets beyond our solar system. And Rory Barnes, a University of Washington astronomer who focuses on astrobiology and the habitability of exoplanets, suspects Star Wars creator George Lucas knew this could happen.
Readings from the Hubble Space Telescope have shed light on a bizarre class of alien planets that have the density of cotton candy.
Astronomers have identified thousands of stars that have planets, and that number could mushroom even faster when waves of next-generation telescopes come online. But where are the best places to look for life?
A newly released study focuses on the most plentiful category of stars in our Milky Way galaxy — M-dwarf stars, also known as red dwarfs — and delivers good news as well as bad news for astrobiologists.
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.
The European Southern Observatory and the billionaire-backed Breakthrough Watch program say they have achieved first light with a new observing instrument designed to spot super-Earths in Alpha Centauri, the nearest star system to our own.
The NEAR instrument, which takes its name from the acronym for “Near Earths in the AlphaCen Region,” has been installed on an 8-meter (26.2-foot) telescope that’s part of ESO’s Very Large Telescope facility in Chile’s Atacama Desert.
NEAR takes advantage of a thermal-infrared coronagraph to block out most of the light coming from the stars in the Alpha Centauri system, a little more than 4 light-years away – including the sunlike stars Alpha Centauri A and B, plus a red dwarf called Proxima Centauri.
Cutting down on that glare makes it easier for an infrared imaging spectrometer known as VISIR to pick up the warm glow of planets orbiting the stars. The upgraded instrumentation, which took three years to develop, should be capable of detecting worlds down to twice the size of Earth.
Where’s the nearest exoplanet with conditions that are right for life? Over the past couple of years, astrobiologists have talked up Proxima Centauri b, which is sitting just 4.2 light-years away.
But Villanova University astrophysicist Edward Guinan favors a world that’s just a bit farther out, at least in astronomical terms. It’s Barnard’s Star b, a super-Earth that orbits Barnard’s Star, 6 light-years from our solar system.
Red dwarf stars have been seen as the biggest potential frontier for alien life, in part because they’re the most common stars in our galaxy. But observations made using the Hubble Space Telescope suggest that the frontier might turn out to be a desert.
“We may have found the limit to habitable planets,” said Carol Grady, a co-investigator on the Hubble observations from Eureka Scientific in Oakland, Calif. She laid out the research team’s findings today at the American Astronomical Society’s winter meeting in Seattle.
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.