Researchers using NASA’s James Webb Space Telescope have officially broken new ground: detecting and analyzing rocky exoplanets orbiting red dwarf stars. A team led by Kevin Stevenson and Jacob Lustig-Yager of Johns Hopkins University’s Laboratory of Applied Physics in Laurel, Maryland has confirmed that LHS 475 b not only exists, but is a small, rocky planet almost the same size. Before Webb, researchers typically targeted planets larger than Jupiter that were 11 times wider than Earth. This will inevitably be the first of many discoveries that Webb’s data will help researchers make as they continue to discover planets elsewhere in our Milky Way galaxy.

Using NASA’s James Webb Space Telescope, researchers have confirmed for the first time an exoplanet, a planet orbiting another star. Officially classified as LHS 475 b, the planet is nearly the same size as ours and 99% the diameter of Earth. The research team is led by Kevin Stevenson and Jacob Lustig-Yager, both of the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

After carefully examining interesting targets pointing to a planet from NASA’s Transiting Exoplanet Survey Satellite (TESS), the team decided to observe it with Webb. The Webb Near Infrared Spectrograph (NIRSpec) captured the planet easily and clearly with only two transit observations. “There is no doubt that there is a planet. Webb’s preliminary data supports that,” he said. “It’s also impressive for the observatory to be a small, rocky planet,” Stevenson added.

“These first observations of a rocky Earth-size planet open the door to many future opportunities with Webb to study the atmospheres of rocky planets,” said Mark Clampin, director of the Astrophysics Division at NASA Headquarters in Washington. “Webb brings us closer to a new understanding of terrestrial worlds beyond our solar system, and the task is just getting started.”

Of all working telescopes, only Webb has the ability to characterize the atmospheres of Earth-sized exoplanets. The team tried to predict what was in the planet’s atmosphere by analyzing the transmission spectrum. They don’t know yet if it has an atmosphere, although the data shows it’s an Earth-sized planet. “The observatory data is incredible,” said Erin May of the Johns Hopkins University Applied Physics Laboratory. “The telescope is so sensitive that it can easily detect a range of molecules, but we can’t yet draw definitive conclusions about the planet’s atmosphere.”