The James Webb Space Telescope has made a hot new find: LHS 475 b, a rocky planet almost exactly the same size as Earth. The first exoplanet spotted by the telescope has 99% of our planet's diameter and is relatively close, 41 light years away in the Octans constellation, NPR reports. It is, however, a few hundred degrees hotter than Earth, making it an unlikely candidate for life. The planet orbits a small, dim star very closely, completing an orbit in just two days. While it's not clear what kind of atmosphere it has, if it has one at all, lead researcher Jacob Lustig-Yaeger at the Johns Hopkins University Applied Physics Laboratory says some possibilities can be ruled out, including a "thick methane-dominated atmosphere, similar to that of Saturn's moon Titan."
Lustig-Yaeger presented the discovery at the American Astronomical Society meeting on Wednesday, the Verge reports. "Over the next few years, and ultimately decades, the search for life on exoplanets will fundamentally rely on the detailed characterization of exoplanet atmospheres," he said. "And the first step on this journey is simply to detect the presence of exoplanet atmospheres." NASA says the team chose to use the Webb telescope's spectrograph technology after reviewing possible targets from NASA’s Transiting Exoplanet Survey Satellite. Most exoplanets previously detected have been gas giants like Jupiter, but Mark Clampin, astrophysics division director at NASA headquarters, says the results "open the door to many future possibilities for studying rocky planet atmospheres."
"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. We’re at the forefront of studying small, rocky exoplanets," Lustig-Yaeger says. "We have barely begun scratching the surface of what their atmospheres might be like." He adds: "With this telescope, rocky exoplanets are the new frontier." Researchers, who describe data from the Webb telescope as "beautiful," hope to learn more about LHS 475b with more observations this summer. (Read more exoplanet stories.)