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.
Not that anyone’s planning on setting up shop there soon: Unless there’s a breakthrough that allows us to travel at a significant fraction of the speed of light, it would take hundreds of thousands of years to get to TRAPPIST-1. But the climate modeling methods developed for the TRAPPIST-1 system could help scientists decide which planets to target first with telescopes capable of analyzing alien atmospheres.
The astronomical team that found the nearest exoplanet at Proxima Centauri has done it again with the reported detection of a super-Earth orbiting Barnard’s Star, the second-closest star system to our own.
The discoverers acknowledge, however, that they’re not completely sure yet.
“After a very careful analysis, we are 99 percent confident that the planet is there,” Spanish astronomer Ignasi Ribas, lead author of a study about the detection published today by the journal Nature, said in a news release. “However, we’ll continue to observe this fast-moving star to exclude possible, but improbable, natural variations of the stellar brightness which could masquerade as a planet.”
Assuming it exists, Barnard’s Star b would be at least 3.2 times as massive as Earth, tracing a 233-Earth-day orbit. It would be as close to its parent star as Mercury is to our own sun — but because Barnard’s Star is a dim red dwarf, surface conditions would be far too chilly for life as we know it. The surface temperature would be about 275 degrees below zero Fahrenheit (-170 degrees Celsius).
NASA’s Kepler planet-hunting telescope now belongs to the ages, with its fuel completely spent and its instruments shut down — but the planet quest continues, thanks to a treasure trove of downloaded data as well as a new generation of robotic planet-hunters.
Space agency officials declared the end of spacecraft operations today, nine and a half years after the car-sized probe was launched. The hydrazine fuel ran out about two weeks ago, signaled by a sharp drop in pressure readings for the propulsion system.
“In the end, we didn’t have a drop of fuel left over for anything else,” Charlie Sobeck, project system engineer at NASA’s Ames Research Center, said during a teleconference.
While searching for a hypothetical Planet Nine, astronomers found a distant mini-world that’s been given a spooky nickname: “The Goblin.”
The icy object was found at a distance of about 80 astronomical units from the sun, which translates to 7.4 billion miles. (One astronomical unit, or AU, equals 93 million miles, which is the distance between Earth and the sun.) That’s more than twice as far away as dwarf planet Pluto.
A research team led by Scott Sheppard of the Carnegie Institution of Science first spotted The Goblin just before Halloween in 2015. That timing, plus the fact that it was given the numerical designation 2015 TG387, gave rise to the trick-or-treat nickname. (T.G. … Get it?)
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.
Has the planet Vulcan been found? Vulcan’s most famous fictional inhabitant, Mr. Spock of “Star Trek” fame, would certainly raise an eyebrow if he heard that astronomers have detected a potentially habitable super-Earth orbiting the star that’s associated with him.
The world orbits a sunlike star that’s a mere 16 light-years away, known as HD 26965 or 40 Eridani A, according to the team behind the Dharma Planet Survey.
In the current Star Trek canon, 40 Eridani A is the star that harbors Spock’s home planet. Some early references pointed to a different star, known as Epsilon Eridani(which is also thought to host at least one exoplanet). But in a 1991 essay, Star Trek creator Gene Roddenberry and a group of astronomers argued that 40 Eridani A, the brightest star in a triple-star system, was a better fit because its 4 billion years of existence provided a wider window for pointy-eared intelligent life to evolve.
The latest findings suggest Roddenberry made the right choice: The planet found at 40 Eridani A is roughly twice Earth’s size, completes an orbit around its parent star every 42 Earth days, and lies just inside the star’s optimal habitable zone, said University of Florida astronomer Jian Ge.
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.
Twelve years after the International Astronomical Union voted in a definition of planethood that reclassified Pluto, the debate goes on.
A newly published study uses the historical record to take aim at the definition’s most controversial clause: the idea that a planet in the solar system has to “clear the neighborhood of its orbit,” so that no other worlds are at a similar orbital distance.
NASA should add a large, technologically advanced space telescope to its lineup to capture direct images of Earthlike planets beyond our solar system, astronomers say in a congressionally mandated report issued today.
The report, published under the aegis of the National Academies of Sciences, Engineering and Medicine, also calls on the National Science Foundation to invest in the next-generation Giant Magellan Telescope and the Thirty Meter Telescope.
The GMT is being built in Chile, with completion set for 2025. The TMT is also due to go into service in the mid-2020s, although the current plan to build it on the top of Hawaii’s Mauna Kea volcano has run into controversy.
But the report makes clear that the search for alien planets will have to focus down on direct images of planets, as well as detailed analysis of exoplanet atmospheres, in order to address questions about the existence of life beyond our solar system.