For the first time, astronomers may have caught a glimpse of an atmosphere around TRAPPIST-1e, an Earth-sized world orbiting a nearby red dwarf star.

Located just 40 light-years away, this rocky planet has long been one of the most promising candidates in the search for a habitable exoplanet.

Now, new research from the University of St Andrews using the James Webb Space Telescope (JWST) suggests TRAPPIST-1e could hold the key ingredient for life as we know it: an atmosphere capable of supporting liquid water.

A planet in the sweet spot

TRAPPIST-1e is one of seven known planets in the TRAPPIST-1 system, four of which sit within the star’s ‘habitable zone’ – a region where liquid water could exist.

Of these, TRAPPIST-1e is considered the most promising candidate for Earth-like conditions.

The presence of water, however, depends entirely on whether the planet has a stable atmosphere, a puzzle that researchers are now piecing together.

James Webb Telescope at the forefront

To probe the planet’s secrets, scientists turned to the JWST, the most advanced space observatory ever built.

Operated by NASA in collaboration with the European and Canadian space agencies, JWST has the power to detect faint signals from distant worlds.

Using its NIRSpec (Near-Infrared Spectrograph) instrument, researchers observed the starlight filtering through TRAPPIST-1e’s potential atmosphere during planetary transits – when the planet passes in front of its star.

Untangling the data

The challenge was immense. The TRAPPIST-1 star, a red dwarf, is covered with starspots that interfere with light readings, masking the delicate signals that might reveal atmospheric gases.

For over a year, the research team meticulously corrected the data to separate the planetary signature from stellar ‘noise.’

Their analysis points to two possible scenarios: TRAPPIST-1e could host a dense atmosphere rich in heavy gases such as nitrogen, or it could be a barren, airless rock.

Why this matters for habitability

If TRAPPIST-1e does indeed possess a nitrogen-dominated atmosphere, the conditions for surface oceans or even ice-covered expanses dramatically increase.

Such an environment would make it one of the strongest candidates yet for a habitable exoplanet.

Even the alternative outcome, a bare rocky planet, would still provide astronomers with valuable insights into planetary formation and survival in harsh stellar environments.

What comes next

The investigation is far from over. The JWST is scheduled to conduct nearly twenty separate transit observations of TRAPPIST-1e in the coming years, compared to just four in this initial phase.

Each new dataset will sharpen scientists’ ability to confirm whether an atmosphere exists and, if so, what it contains.

The results could provide the clearest evidence yet of habitable conditions outside our solar system.

A global scientific effort

This pioneering work is part of the JWST-TST DREAMS (Deep Reconnaissance of Exoplanet Atmospheres through Multi-instrument Spectroscopy) programme.

The project unites more than 30 researchers from the UK, USA, and India under the leadership of Cornell University.

Together, the team is pushing the boundaries of what is possible in the quest to identify a habitable exoplanet.

A new era in astronomy

The TRAPPIST-1e discovery underscores a transformative moment for astronomy. For decades, the idea of detecting life-supporting worlds was the stuff of science fiction.

Now, with the capabilities of the James Webb Space Telescope, humanity is edging closer to answering one of its oldest questions: Are we alone in the Universe?