The Future Is Here
We may earn a commission from links on this page

Webb Space Telescope Finds Its First Exoplanet

The distant world is about the same size as Earth, but questions surrounding its atmosphere remain.

We may earn a commission from links on this page.
An artist’s impression of the exoplanet, LHS 475 b, and the star it orbits.
An artist’s impression of the exoplanet, LHS 475 b, and the star it orbits.
Illustration: NASA, ESA, CSA, L. Hustak (STScI)

The incredibly powerful Webb Space Telescope—which has fed us dazzling images of the cosmos since July—has officially found its first exoplanet, a world that is approximately the same size as Earth.

The planet is named LHS 475 b, and it’s 41 light-years away with a diameter that is 99% Earth’s. LHS 475 b’s presence was suspected by researchers who observed hints of the planet using NASA’s Transiting Exoplanet Survey Satellite, but they were able to confirm its existence with Webb’s Near-Infrared Spectrograph. Webb has shed light on already-discovered exoplanets before this, but confirming the existence of LHS 475 b is the first time the telescope has located an exoplanet in the night sky, which is one of its core scientific missions.


“These first observational results from an Earth-sized, rocky planet open the door to many future possibilities for studying rocky planet atmospheres with Webb,” said Mark Clampin, astrophysics division director at NASA headquarters in Washington, in a statement. “Webb is bringing us closer and closer to a new understanding of Earth-like worlds outside the Solar System, and the mission is only just getting started.”


While the telescope was able to confirm that the planet was a rocky, Earth-like exoplanet, it’s not yet clear if LHS 475 b has an atmosphere. The researchers were, however, able to determine that the surface of the planet is a few hundred degrees warmer than Earth. More observations of the planet are scheduled to occur this summer.

“The observatory’s data are beautiful,” said Erin May, an astrophysicist in the Johns Hopkins University Applied Physics Laboratory and a collaborator on the discovery. “The telescope is so sensitive that it can easily detect a range of molecules, but we can’t yet draw any definitive conclusions about the planet’s atmosphere,” she said in an ESA release.

The Webb Space Telescope, launched just over a year ago, continues to peer into the depths of space to help us take a closer look at our universe. Webb’s mission is to help hunt for exoplanets—including ones that could support lifeand this new milestone is just the first of many to come.