New observations from the James Webb Space Telescope (JWST) have narrowed the possibilities for the atmosphere of TRAPPIST-1e, a rocky planet about forty light-years away in the TRAPPIST-1 system, boosting its status as a leading candidate for habitability.

Scientists now suggest that while a thick, hydrogen-rich atmosphere is highly unlikely, a secondary atmosphere rich in heavier gases like nitrogen remains plausible.

The analysis draws from four planetary transits observed in 2023, using JWST’s Near-Infrared Spectrograph (NIRSpec) and other instruments under the DREAMS (Deep Reconnaissance of Exoplanet Atmospheres through Multi-instrument Spectroscopy) program.

These early observations have enabled scientists to rule out some atmosphere types—especially primordial, hydrogen-dominated envelopes—and to reject atmospheres similar to those of Venus or Mars in thickness or CO₂ content.

A new study led by researchers including Ana Glidden, Ryan MacDonald, Sara Seager, and co-authors used transmission spectroscopy to compare observed spectra to atmospheric models.

The data remain consistent with a nitrogen-rich atmosphere with possible trace gases such as methane—or alternatively, no atmosphere at all (a bare rocky world).

One of the biggest challenges is the star itself: TRAPPIST-1 is a red dwarf, prone to flares and starspots, which interfere with the starlight used to detect atmospheric signals.

To compensate, the team is observing transits of TRAPPIST-1b (thought to be barren) alongside those of TRAPPIST-1e, to help isolate and subtract stellar noise.

The researchers are planning about fifteen more transit observations of TRAPPIST-1e by the end of this year.

These will significantly improve the data, narrowing uncertainty about how dense any atmosphere might be, and possibly detecting spectral signatures of greenhouse gases such as methane or carbon dioxide.

TRAPPIST-1e orbits comfortably within its star’s habitable zone, receiving roughly sixty percent of the stellar radiation Earth gets.

Its size and density are similar to Earth’s, making it one of the strongest candidates among known exoplanets for maintaining liquid water on its surface—provided an atmosphere is present to regulate temperature and protect against stellar radiation.

If TRAPPIST-1e is shown to have a nitrogen-dominated atmosphere, it would be a landmark discovery: the first rocky exoplanet in the habitable zone outside our solar system confirmed to host an atmosphere.

Even if it lacks one, the results will refine our understanding of atmospheric loss, stellar radiation’s impact, and planetary evolution around red dwarfs.

These findings mark a turning point in the search for life beyond Earth.

With the JWST already delivering observations of transits, and with many more scheduled, astronomers may soon confirm whether TRAPPIST-1e is a world of oceans and atmosphere—or a rocky shell bathed in starlight.