Signs of an Earth-equivalent atmosphere discovered around a planet orbiting another star

In an exciting breakthrough for astronomy, a team of researchers has published two studies in The Astrophysical Journal Letters about the potential habitability of TRAPPIST-1e, one of the seven Earth-sized planets orbiting the TRAPPIST-1 star.

The TRAPPIST-1 system, discovered several years ago, has been a subject of interest due to its proximity and the number of planets it hosts. However, the frequent flares from the low-luminosity star have made the planets, including TRAPPIST-1b, c, and d, inhospitable, with little to no atmosphere.

However, TRAPPIST-1e, with 69 percent of Earth's mass, could potentially have a climate similar to our planet, provided it can match Earth's greenhouse effect. The team used longer wavelengths than previous efforts to gain extra confidence in their observations of TRAPPIST-1e.

Three of these planets, including TRAPPIST-1e, lie within the system's habitable zone, increasing the possibility of finding a world suitable for life. The JWST observations of TRAPPIST-1e suggest that it may have an atmosphere, but the initial observations cannot yet rule out a bare rock with no atmosphere.

The JWST observations of TRAPPIST-1e will increase from four to nearly twenty in the coming years, offering more opportunities to study the planet's atmosphere. The team has excluded some possibilities, such as an atmosphere dominated by molecular hydrogen, and finds a Venus-like, carbon dioxide-rich atmosphere unlikely, but not impossible.

The JWST, with its advanced capabilities, has studied the atmospheres of gas giants, but these were mainly practice runs for finding atmospheres around Earth-like worlds like TRAPPIST-1e. If a nitrogen-rich atmosphere is confirmed for TRAPPIST-1e, it will intensify the search for signs of oxygen or other gases that might hint at life.

The team's findings have been met with a mix of excitement and caution. The presence of a substantial atmosphere on TRAPPIST-1e would make the presence of liquid water at the surface likely. However, the JWST can't definitively determine if an atmosphere is present based on a single transit, but by stacking data from multiple transits, it is hoped we will soon know if these worlds have air.

The authors of the two publications about the atmosphere of TRAPPIST-1e include Ana Glidden as lead author of one paper and co-authors such as Sara Seager, with contributions from researchers at MIT, University of Arizona, Johns Hopkins University, University of Michigan, the Space Telescope Science Institute, and members of the JWST-TST DREAMS Team. Ryan MacDonald is also mentioned as a contributor to the atmospheric analysis.

As we continue to explore the cosmos, the discovery of potentially habitable planets like TRAPPIST-1e offers a glimmer of hope for finding life beyond our own planet. Today is an exciting time for astronomy as we have the telescope and tools to search for habitable conditions in other star systems.

Signs of an Earth-equivalent atmosphere discovered around a planet orbiting another star