Could TRAPPIST-1 e Host Life? NASA Webb probes Earth-sized exoplanet in habitable zone

This artist’s concept shows the volatile red dwarf star TRAPPIST-1 and its four most closely orbiting planets, all of which have been observed by NASA’s James Webb Space Telescope. (Image: NASA)

Scientists are studying the exoplanet TRAPPIST-1 e closely. NASA’s James Webb Space Telescope is leading this effort. Researchers want to know if life could exist there. What have they discovered so far about planet e’s atmosphere?

What makes TRAPPIST-1e important for study?

TRAPPIST-1 e orbits a small, cool red dwarf star. It is one of seven Earth-sized planets there. Scientists are curious because it lies in the habitable zone. This means the planet’s surface could support liquid water. The condition depends on whether an atmosphere exists. Without an atmosphere, surface water would not survive.

The team used Webb’s NIRSpec instrument for this work. They observed the planet during four transits of its star. Starlight passes through the planet’s atmosphere, if present. This light carries clues about atmospheric chemicals. Each transit helps scientists collect more data. They now analyse four transit events in detail. Two scientific papers have been published today.

What are the key findings so far?

Researchers say planet e probably lacks a primary atmosphere. Stellar flares from TRAPPIST-1 likely stripped away hydrogen-helium layers. A secondary atmosphere could still exist, they say. The chance of any atmosphere is still equal. The team applied new methods to study the data. Carbon dioxide dominance seems unlikely, similar to Venus or Mars. But there are no direct solar system comparisons.

Liquid water might exist under a greenhouse effect. Carbon dioxide could stabilise the atmosphere and keep warmth. Scientists suggest a global ocean or small liquid area. Tidal locking causes one side of the planet to face the star permanently. This allows for a warm day side and frozen night side. Observations do not rule out enough carbon dioxide present.

What makes the observation method innovative?

Scientists plan 15 more transits with a special strategy. They observe planets b and e transiting back-to-back. Planet b likely has no atmosphere, only a bare rock. Comparing both transits helps separate star and planet signals. Any chemicals seen only during planet e’s transit come from its atmosphere. This reduces interference from the star’s variability.

Ana Glidden of MIT describes the process as exciting. She said it is amazing to analyse starlight details. The research helps understand Earth-sized planets 40 light-years away. Néstor Espinoza and Natalie Allen lead the project. Their team is part of the DREAMS collaboration.

The study marks early steps in exoplanet science. It shows Webb’s powerful tools at work. Researchers await future data for clearer answers.