A cosmic lottery? TRAPPIST-1d lacks an Earth-like atmosphere

Space · Published 22 October 2026 Swipe more like this →

In short: Astronomers are searching for Earth's twins among the stars, but the latest data from the James Webb Space Telescope suggests we might have won the cosmic lottery. One of the most promising candidates for a habitable world just failed the atmosphere test.

The TRAPPIST-1 system, 40 light-years away, is a primary target for finding life, hosting seven Earth-sized rocky planets orbiting a red dwarf. Four reside in the "habitable zone," where temperatures could theoretically allow for liquid surface water. However, the James Webb Space Telescope (JWST) recently used its Near-Infrared Spectrograph (NIRSpec) to analyse TRAPPIST-1d, the third planet from its star. The results were disappointing: the telescope detected no signatures of water, methane, or carbon dioxide—the essential greenhouse gases required to retain heat.

TRAPPIST-1d is a unique laboratory, sitting on the cusp of the habitable zone while orbiting at only 2 percent of the distance between Earth and the Sun. Because its host star is a dim, relatively cold red dwarf, its "Goldilocks zone" is much tighter than our own. Despite these conditions, the study led by Caroline Piaulet-Ghorayeb suggests TRAPPIST-1d cannot be considered an "Earth twin" or "cousin" at this stage.

The lack of a detectable atmosphere leaves three possibilities: a Martian-like atmosphere of minimal density, a lifeless stone devoid of gases, or very thick, high-altitude clouds, similar to Venus, blocking detection. The system still holds four other planets for follow-up study.

theme-key-mechanisms mood-reflective difficulty-2 topics-["exoplanets", "astrophysics", "space-exploration"]

claims-["TRAPPIST-1 is 40 light-years away", "The system has 7 Earth-sized rocky planets", "TRAPPIST-1d orbits its star in 4 Earth days", "TRAPPIST-1d is 2 percent of the distance from its star compared to Earth's distance from the Sun", "JWST failed to detect water, methane, or carbon dioxide on TRAPPIST-1d", "TRAPPIST-1d is the third planet from its star"]

canvas-type-data canvas-data-title-"TRAPPIST-1 System Context" canvas-data-series-

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

• Seven rocky worlds orbit a tiny star just 40 light-years away
• Seven Earth-sized planets discovered around a single ultra-cool dwarf star
• Seven Earth-sized worlds orbit a star smaller than Jupiter
• Seven Earth-sized worlds orbit a single, tiny star
• Is there an atmosphere on TRAPPIST-1e? The search for liquid water
• NASA's Kepler mission has identified 833 new candidate planets
• Could a volcanic moon orbit one of the galaxy's hottest planets?
• Astronomers detect one of the youngest fully formed exoplanets ever found
• Could an eighth planet be hiding within the TRAPPIST-1 system?
• The mysterious dimming of Tabby’s Star was not caused by aliens
• The closest neighbor to Earth might be a desolate, airless wasteland
• How we will finally photograph Earth-like worlds in deep space

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