Recent findings from the James Webb Space Telescope (JWST) have dampened hopes for finding Earth-like atmospheres around the TRAPPIST-1 planets. The telescope did not detect any atmosphere on TRAPPIST-1d, the third planet from its star. This follows previous results where atmospheres weren’t found on the two closest planets, TRAPPIST-1b and TRAPPIST-1c.
Still, there are four other planets in this system that may offer a glimmer of hope for habitability. At least two or three of them are in the “habitable zone,” where conditions might allow for liquid water to exist if they have the right atmosphere. Caroline Piaulet-Ghorayeb, an astrophysicist from the University of Chicago, explained, “Ultimately, we want to know under what conditions environments similar to ours might exist elsewhere.”
The JWST’s technique, known as transmission spectroscopy, works by analyzing the light from stars as planets pass in front. This method can reveal if certain gases, like water or methane, are present in an atmosphere. However, for TRAPPIST-1d, no significant signs of these gases were detected. Piaulet-Ghorayeb suggested there might be several reasons for this lack of detection, including the possibility of a very thin atmosphere or thick clouds blocking signals.
The star itself poses challenges. Red dwarfs, while smaller and cooler, often experience violent radiation flares. These flares can strip away atmospheres from nearby planets. This may be the fate of TRAPPIST-1b, c, and d. Despite this, two further planets—e and f—lie in a more promising part of the habitable zone. Planet g is on the outer edge, similar to Mars in our solar system, while planet h appears too cold for an Earth-like atmosphere.
Piaulet-Ghorayeb reassured that all hope isn’t lost, stating that the outer planets could still harbor significant atmospheric components. Detection of their atmospheres, however, will be more challenging due to their distance from the star. As science continues to evolve, other nearby systems hold promise too. For instance, there are more red dwarfs in our galaxy, and some may have rocky planets in their habitable zones, like Proxima Centauri b.
The ongoing quest to discover more about these distant worlds is crucial. Research from the European Space Agency’s upcoming PLATO mission, set to launch in December 2026, aims to accelerate this search, potentially revealing new insights into habitable planets.
For the latest on the search for atmospheres around TRAPPIST-1d, check the findings published in The Astrophysical Journal.
