Searching for life beyond Earth has rapidly advanced in recent years. However, directly imaging an exoplanet and all their incredible features remain elusive given the literal astronomical distances from Earth. Therefore, astronomers have settled by exploring exoplanet atmospheres for signatures of life, also called biosignatures. This is currently conducted by analyzing the starlight that passes through an exoplanet’s atmosphere, known as spectroscopy, as it passes in front of its star, also called a transit. But improvements continue to be made to better explore exoplanet atmospheres, specifically cleaning up messy data.
Now, a researcher from Ludwig Maximilian University (LMU) in Germany has introduced a new model for exploring exoplanet atmospheres, with his findings being discussed in a recent study published in *The Astrophysical Journal*. Longstanding models have provided scientists with limited atmospheric data due to mathematical restrictions within the models. But this new study essentially fills the missing gaps in mathematical modeling, offering researchers with improved methods to observe new atmospheric datasets while streamlining essential data from the noise.
“This analytical solution opens the door to a new generation of much faster, more transparent, and more realistic atmospheric analysis and retrieval techniques,” said Dr. Leonardos Gkouvelis, who is a LMU physicist and sole author of the study. “They will be essential to maximize the scientific return of current and future missions such as JWST [James Webb Space Telescope] and ARIEL [Atmospheric Remote-sensing Infrared Exoplanet Large-survey], and to advance the detailed characterization of potentially habitable worlds beyond the solar system.”
As noted, spectroscopy is currently employed to study exoplanet atmospheres by analyzing the light that passes through as the exoplanet passes in front of its star. Astronomers have used spectroscopy for more than 200 years, initially through studying the Sun and eventually other stars, but JWST has taken this practice to a whole new level by analyzing the starlight passing through exoplanet atmospheres and identifying key molecules. This includes a diverse list of rocky and gaseous exoplanets where JWST identified a myriad of known atmospheric molecules or even identifying that certain rocky exoplanets potentially lack any atmosphere.
An example of a gaseous exoplanet includes a 2023 study published in Nature where JWST identified water, carbon dioxide, carbon monoxide, and sodium in the atmosphere of WASP-39b. Along with having a radius approximately 25 percent larger than Jupiter, it is located approximately 700 light-years from Earth and is designated as the JWST’s first studied experiment. Examples of rocky exoplanet atmospheres that JWST has explored include the TRAPPIST-1 system, which consists of seven Earth-sized exoplanets and has garnered significant scientific interest due to several of them orbiting in its star’s habitable zone, including TRAPPIST-1 e, TRAPPIST-1 f, and TRAPPIST-1 g.
However, recent studies have yet to draw definitive conclusions regarding whether these three exoplanets have atmospheres, including a 2025 study published in *The Astrophysical Journal Letters* discussing TRAPPIST-1 e, a series of papers that discuss TRAPPIST-1 f, and a study presented at the American Astronomical Society Meeting #241 in 2023 discussing TRAPPIST-1 g potentially having an atmosphere containing water, carbon dioxide, and methane, but remain inconclusive.
Dr. Gkouvelis mentioned how his study could influence ARIEL, which is a planned space telescope from the European Space Agency whose primary objective will be to observe and study at least 1,000 known exoplanets discovered using the transit method. This will essentially be a combination of NASA’s now-retired Kepler mission, which identified exoplanets via the transit method, and NASA’s JWST, though ARIEL is slated to be smaller than JWST while focusing primarily on exoplanets, whereas JWST has a myriad of non-planetary mission objectives.
How will this new theory help astronomers explore exoplanet atmospheres in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!