TRAPPIST-1b Could Have Carbon Dioxide-Rich Atmosphere, Study Reveals

The innermost planet of the TRAPPIST-1 system, TRAPPIST-1b, may possess a carbon dioxide-rich atmosphere, according to research published in Nature Astronomy on December 16. The TRAPPIST-1 system, which lies 40 light-years from Earth and includes seven Earth-sized exoplanets, has intrigued astronomers since its discovery in 2017. Earlier studies suggested that these planets lacked atmospheres due to intense stellar radiation. However, recent data from the James Webb Space Telescope (JWST) raises the possibility of a hazy, carbon dioxide-heavy atmosphere on TRAPPIST-1b.

Findings on Atmospheric Composition

As per reports, the study highlights new measurements taken at 12.8 micrometres, showing evidence of a reflective haze in TRAPPIST-1b's upper atmosphere. Researchers believe this haze may cause upper layers to emit rather than absorb radiation, challenging previous assumptions. Speaking to KU Leuven News, Leen Decin, co-author of the study and researcher at KU Leuven in Belgium, noted, that the two data points for TRAPPIST-1b allows them to explore various scenarios for its atmosphere, whether it exists or not.

Volcanism and Surface Conditions

The research also indicates elevated surface temperatures, suggesting potential volcanic activity. Similar dynamics have been observed on Saturn's moon Titan. According to Michiel Min from the SRON Netherlands Institute for Space Research, who contributed to the study, in a statement, the atmospheric chemistry of TRAPPIST-1b is expected to be unlike anything seen on Titan or in the solar system.

Ongoing Studies

The team aims to examine heat distribution across the planet's surface to determine whether an atmosphere is present. Michaël Gillon, an astronomer at the University of Liège who led the discovery of the TRAPPIST-1 system, explained to Nature Astronomy that an atmosphere would facilitate heat redistribution from the day to night side of the planet. Without it, heat transfer would be minimal.
These findings may reshape understanding of atmospheres around exoplanets near red dwarf stars, according to experts.