The james webb space telescope first detected the presence of CO2 in the atmosphere of an exoplanetthat is, a planet outside our solar system, a discovery that demonstrates its immense capabilities and that excites scientists.
The planet in question is a hot gas giant where life as we know it would be impossible, but this discovery implies that these observations can also be made on rocky planets – with the ultimate goal of determining if one of them harbors conditions favorable to life. -.
“For me, it is a door that opens for future studies of super-Earths, even of Earths,” Pierre-Olivier Lagage, an astrophysicist at the Atomic Energy Commission (CEA) and one of the three co-authors of the study, told AFP on Thursday. these works published in the scientific journal Nature. “My first reaction: wow, we really do have the potential to detect the atmospheres of Earth-sized planets,” astrophysics professor Natalie Batalha of the University of California, Santa Cruz, tweeted.
700 light years away
The detection of CO2 will also allow us to learn more about the formation of this planet, called WASP-39 b, which was discovered in 2011, NASA said. Located 700 light-years away, the planet is about a quarter the mass of Jupiter and is very close to its sun.
This planet was selected based on several criteria that made it easier to observe at a time when scientists are still evaluating the capabilities of the telescope, which revealed its first images less than two months ago. WASP-39 b periodically passes in front of its sun (with a four-day orbit).
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For its observations, the James Webb uses the transit method, that is, when the planet passes in front of its star, the telescope captures the tiny resulting variation in brightness. It then analyzes the light “filtered” through the planet’s atmosphere. The different molecules present in the atmosphere leave specific marks that allow their composition to be determined.
The Hubble and Spitzer telescopes had already detected water vapor, sodium and potassium in the atmosphere of this planet, but the James Webb was able to go further thanks to its enormous infrared sensitivity. In the NASA statement, Zafar Rustamkulov of Johns Hopkins University comments on what he felt when the presence of CO2 was clearly established: “It was a special moment, reaching a turning point in exoplanet science.”