August 25, 2022
17:26
Details of this discovery will appear in the next issue of Nature. This is an important step in the search for stars that could potentially host life.
Launched at the end of 2021 by NASA, the new James Webb space telescope has delivered a spectacular scientific result. For the first time, carbon dioxide could be clearly detected in the atmosphere of an exoplanet.
Scientists from the University of Geneva (UNIGE), the University of Bern (UNIBE) and the National Research Center (PRN) PlanetS took part in this discovery. These results will be published next week in the journal Naturesaid UNIGE in a press release on Thursday.
The exoplanet WASP-39b is a hot gas giant transiting in front of its star. The latter, similar to the Sun, is located at 700 light years from Earth. When a planet passes right in front of its star, some of the light from the star passes through the planet’s atmosphere before reaching the telescope.
“The atmosphere then filters certain colors more than others.this depending on the material that composes it, its thickness, and the presence or absence of clouds”, explains Monika Lendl, co-author of the study, professor in the UNIGE Department of Astronomy and member of the PRN PlanetS.
Worlds suitable for life
“This is the first time that carbon dioxide has been clearly detected on a planet outside the solar system.”
“By using the James-Webb telescope to break light down into its colors, we can identify characteristic ‘fingerprints’ of different gases and determine the composition of the atmosphere,” she continues. Using the near-infrared spectrograph (NIRSpec) of the James-Webb telescope, the research team was able to detect the fingerprint of carbon dioxide in the light that passed through WASP-39b’s atmosphere.
“As soon as we saw the data, it was clear we were dealing with a spectacular discovery, rejoices Dominique Petit dit de la Roche, researcher at UNIGE, co-author of the study and member of the PRN PlanetS. This is the first time that carbon dioxide has been clearly detected on a planet outside the solar system.”
Understanding the composition of a planet’s atmosphere helps to better understand the origin of the planet and its evolution. By clearly detecting the presence of CO2 in the atmosphere of distant exoplanets, an essential step in the search for worlds suitable for life has been taken.
A $10 billion engineering gem, the James Webb Telescope was launched into space about seven months ago, and is 1.5 million kilometers from Earth. The telescope began its scientific work in June 2022.