The team’s results were presented at a press conference of the American Astronomical Society (AAS) on Wednesday, Jan. LHS 475 b is relatively close, at only 41 light-years away, in the constellation Octans. “With this telescope, rocky exoplanets are the new frontier.” “And it is only the first of many discoveries that it will make.” Lustig-Yaeger agreed. “This rocky planet confirmation highlights the precision of the mission’s instruments,” Stevenson said. The researchers’ findings have opened the possibilities of pinpointing Earth-sized planets orbiting smaller red dwarf stars. Although LHS 475 b is closer to its star than any planet in our solar system, its red dwarf star is less than half the temperature of the Sun, so the researchers project it still could have an atmosphere. The researchers also confirmed that the planet completes an orbit in just two days, information that was almost instantaneously revealed by Webb’s precise light curve. “We have barely begun scratching the surface of what their atmospheres might be like.” “We’re at the forefront of studying small, rocky exoplanets,” Lustig-Yaeger said. Webb also revealed that the planet is a few hundred degrees warmer than Earth, so if clouds are detected, it may lead the researchers to conclude that the planet is more like Venus, which has a carbon dioxide atmosphere and is perpetually shrouded in thick clouds. The researchers are scheduled to obtain additional spectra with upcoming observations this summer. Even more precise measurements are required for the team to distinguish a pure carbon dioxide atmosphere from no atmosphere at all. “Counterintuitively, a 100% carbon dioxide atmosphere is so much more compact that it becomes very challenging to detect,” said Lustig-Yaeger. The team also notes that while it’s possible the planet has no atmosphere, there are some atmospheric compositions that have not been ruled out, such as a pure carbon dioxide atmosphere. “It can’t have a thick methane-dominated atmosphere, similar to that of Saturn’s moon Titan.” “There are some terrestrial-type atmospheres that we can rule out,” explained Lustig-Yaeger. “The telescope is so sensitive that it can easily detect a range of molecules, but we can’t yet make any definitive conclusions about the planet’s atmosphere.”Īlthough the team can’t conclude what is present, they can definitely say what is not present. “The observatory’s data are beautiful,” said Erin May, also of the Johns Hopkins University Applied Physics Laboratory. Although the data show that this is an Earth-sized terrestrial planet, they do not yet know if it has an atmosphere. The team attempted to assess what is in the planet’s atmosphere by analyzing its transmission spectrum. “Webb is bringing us closer and closer to a new understanding of Earth-like worlds outside our solar system, and the mission is only just getting started.”Īmong all operating telescopes, only Webb is capable of characterizing the atmospheres of Earth-sized exoplanets.

“These first observational results from an Earth-size, rocky planet open the door to many future possibilities for studying rocky planet atmospheres with Webb,” agreed Mark Clampin, Astrophysics Division director at NASA Headquarters in Washington. “The fact that it is also a small, rocky planet is impressive for the observatory,” Stevenson added. Webb’s pristine data validate it,” said Lustig-Yaeger. “There is no question that the planet is there. Webb’s Near-Infrared Spectrograph (NIRSpec) captured the planet easily and clearly with only two transit observations. The team chose to observe this target with Webb after carefully reviewing targets of interest from NASA’s Transiting Exoplanet Survey Satellite (TESS), which hinted at the planet’s existence. The research team is led by Kevin Stevenson and Jacob Lustig-Yaeger, both of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland. Formally classified as LHS 475 b, the planet is almost exactly the same size as our own, clocking in at 99% of Earth’s diameter. Researchers confirmed an exoplanet, a planet that orbits another star, using NASA’s James Webb Space Telescope for the first time.

7 new exoplanets discovered