Astronomers Discover Potential Atmosphere on Exoplanet TRAPPIST-1e

New research has revealed the potential presence of an atmosphere around the Earth-sized exoplanet TRAPPIST-1e, located approximately 40 light-years from Earth. A study published by a team from the University of St Andrews in the Astrophysical Journal Letters suggests that the planet may possess oceans or an icy surface, which could indicate conditions suitable for life.

The research marks the first significant attempt to investigate the atmosphere and surface habitability of TRAPPIST-1e using the James Webb Space Telescope (JWST). As the fourth planet orbiting the red dwarf star TRAPPIST-1, it lies firmly within the star’s habitable zone, where temperatures could allow for the existence of liquid water if an atmosphere is present.

The findings indicate several possible scenarios, including the exciting prospect of an atmosphere. Dr. Ryan MacDonald, a lecturer in extrasolar planets at the University of St Andrews, emphasized the long-standing interest in TRAPPIST-1e for atmospheric studies. He noted, “TRAPPIST-1e has long been considered one of the best habitable zone planets to search for an atmosphere.”

Challenges arose when researchers analyzed data from 2023, as they discovered that the system’s red dwarf star was contaminating their observations. This interference complicated the search for an atmosphere, prompting the team to spend over a year correcting the data to eliminate the star’s impact.

Advanced Techniques Uncover Potential Atmosphere

In an innovative approach, the researchers utilized the JWST’s powerful NIRSpec (Near-Infrared Spectrograph) instrument to observe TRAPPIST-1e as it passed in front of its star. During this transit, starlight filtering through the planet’s atmosphere—if it exists—would be partially absorbed, resulting in measurable changes in the light spectrum. These changes can inform astronomers about the chemicals present in the atmosphere.

Nonetheless, astronomers must also account for starspots, which are local magnetic field-generated spots on the surface of the red dwarf star. This adds a layer of complexity to their analysis. Dr. MacDonald, who contributed to the spectrum analysis of TRAPPIST-1e, mentioned, “We are seeing two possible explanations. The most exciting possibility is that TRAPPIST-1e could have a so-called secondary atmosphere containing heavy gases like nitrogen. But our initial observations cannot yet rule out a bare rock with no atmosphere.”

With each additional observation, researchers are gaining clearer insights into the atmospheric composition of TRAPPIST-1e. The team is currently obtaining further JWST observations to enhance their search for an atmosphere, planning to increase the number of observations from four to nearly 20 in the coming years.

Dr. MacDonald expressed enthusiasm about the future of this research, stating, “We finally have the telescope and tools to search for habitable conditions in other star systems, which makes today one of the most exciting times for astronomy.” The ongoing exploration of TRAPPIST-1e represents a significant step in the quest to understand the potential for life beyond Earth.