Webb finds a rocky world nearly identical to Earth's size

Space · Published 23 October 2026 · Updated 23 October 2026 Swipe more like this →

In short: The James Webb Space Telescope has officially confirmed its first exoplanet, a small rocky world that mirrors our own home. While many exoplanets are gas giants, this discovery marks a pivotal shift toward characterizing terrestrial planets and understanding the diversity of Earth-like worlds across the cosmos.

The discovery of LHS 475 b represents a landmark achievement for the James Webb Space Telescope (JWST). While the observatory has spent its first years investigating various celestial bodies, this specific planet stands out because it is almost exactly the same size as Earth, measuring roughly 99% of our planet's diameter. The research team, led by Kevin Stevenson and Jacob Lustig-Yaeger of the Johns Hopkins University Applied Physics Laboratory, identified the target after reviewing data from the Transiting Exoplanet Survey Satellite (TESS). Using the Near-Infrared Spectrograph (NIRSpec), the team captured clear data from just two transit observations, providing definitive proof of the planet's existence. What makes LHS 475 b particularly significant is its classification as a small, rocky planet. This is a major milestone because, while many telescopes can detect large gas giants, only Webb possesses the sensitivity required to characterize the atmospheres of Earth-sized terrestrial planets.

Scientists are currently analyzing the transmission spectrum of the planet; while the data shows a flat line—meaning they cannot yet confirm if an atmosphere exists—the clarity of the data provides a baseline for future atmospheric studies. This opens a new door for understanding whether such rocky worlds possess the chemical signatures necessary for life. Beyond this specific discovery, Webb is also uncovering other diverse worlds, such as the extremely low-mass TWA 7b, which is about 100 times the mass of Earth. By combining these findings, astronomers are beginning to build a comprehensive map of planetary formation. From the debris rings of young stars to the habitable zones of red dwarfs, Webb is providing the high-resolution data needed to determine which of these distant worlds might one day be considered potentially habitable.

, 388,

General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.

Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?

Related

• The James Webb Space Telescope Successfully Unfolds Its Massive Mirror in Deep Space
• JWST captures the coldest and oldest exoplanet ever imaged
• Beyond the Habitable Zone: JWST Unveils Worlds of Sand and Methane
• Astronomers discover the most Earth-like exoplanet found to date in a habitable zone
• The James Webb Space Telescope is built to study the early universe
• The Super-Earth that challenges our definition of a second home
• Could an eighth planet be hiding within the TRAPPIST-1 system?
• NASA's Kepler mission has identified 833 new candidate planets
• The closest neighbor to Earth might be a desolate, airless wasteland
• Astronomers detect one of the youngest fully formed exoplanets ever found
• Could one of our neighbors be a binary planet system?
• The mysterious dimming of Tabby’s Star was not caused by aliens

More in Exoplanets · More in Space · Latest · A–Z · All topics