The James Webb Space Telescope is revealing an exoplanet’s atmosphere like never before.

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NASA’s James Webb Space Telescope has recorded another first: a molecular and chemical glimpse of the skies of a distant world. While Webb and other space telescopes, including NASA’s Hubble and Spitzer, had previously detected isolated components of this planet’s atmosphere, Webb’s new measurements provide a full catalog of atoms, molecules, and even signs of active chemistry and clouds.

The latest data also gives an idea of ​​what these clouds look like up close: broken rather than one uniform blanket over the planet. The telescope’s highly sensitive instruments aim at the atmosphere of WASP-39 b, a “hot Saturn planet” (a planet about the mass of Saturn, but in an orbit closer than Mercury) orbiting a star about 700 light-years away. turns up.

The results bode well for the ability of Webb’s tools to explore all kinds of exoplanets – planets around other stars – that the scientific community hopes. This includes examining the atmospheres of smaller, rocky planets such as those in the TRAPPIST-1 system. “We observed the exoplanet using multiple instruments that together produce a wide range of infrared radiation and a large number of chemical signatures that lead to [deze missie] “It was inaccessible. Data like this is a game changer,” said Natalie Batalha, an astronomer at the University of California, Santa Cruz who contributed to and co-authored the new study.

The series of discoveries has been detailed in a series of five new scientific papers, three of which have been published and two are pending. Among the unprecedented discoveries is the first observation in an exoplanet’s atmosphere of sulfur dioxide (SO2), a molecule produced by chemical reactions initiated by high-energy light from the planet’s parent star. On Earth, the protective ozone layer in the upper atmosphere forms in a similar way. said Shang-Min Cai, a researcher at the University of Oxford in the United Kingdom and lead author of the paper explaining the origin of sulfur dioxide in the atmosphere of WASP-39 b. “I see this as a promising prospect to work with [deze missie] Understanding the Atmospheres of the Exoplanets.”

This led to the first one: scientists apply computer models of photochemistry to data that require a full explanation of this physics. The resulting modeling improvements will help build technological knowledge to interpret possible signs of habitability in the future. “Planets are formed and transformed by their orbit in the radiation pool of the host star,” Batalha said. “On Earth, these transitions can make life possible.”

Because it is so close to its host star — eight times closer than Mercury is to our sun — it is also a laboratory for studying the effects of radiation from host stars on exoplanets. A better understanding of the star-planet relationship should lead to a better understanding of how these processes affect the diversity of planets observed in the galaxy. To see the light from WASP-39 b, Webb tracked the planet as it passed in front of its star, filtering some of the star’s light through the planet’s atmosphere. Different types of chemicals in the atmosphere absorb different colors of the starlight spectrum, so the missing colors tell astronomers which molecules are present. By viewing the universe in infrared light, Webb can pick up chemical signatures that cannot be seen in visible light.

Other components of the atmosphere detected by the Webb telescope are sodium (Na), potassium (K) and water vapor (H2O). This confirms previous observations from space and ground-based telescopes, and it also finds additional signatures of water, at these longer wavelengths, which have not been observed before. Webb also saw CO2 at a higher resolution, yielding twice as much data as previous observations. Meanwhile, carbon monoxide (CO) was observed, but clear signs of both methane (CH) and hydrogen sulfide (HS) were missing from Webb’s data. When present, these molecules occur in very low concentrations.

To capture this wide spectrum of WASP-39b’s atmosphere, an international team of hundreds of people independently analyzed data from four of Webb’s telescope’s precisely calibrated instrument modes.

“We expected something [de telescoop] “It will appear to us, but it was much more subtle, diverse and beautiful than I actually thought,” said Hannah Wakeford, an astrophysicist at the University of Bristol in the UK who studies exoplanet atmospheres.

With this whole network of chemical components in an exoplanet’s atmosphere, scientists also get a picture of the abundance of different elements in relation to each other, such as the carbon/oxygen ratio or the potassium/oxygen ratio. This, in turn, provides insight into how this planet – and perhaps others – formed in its early years from the disk of gas and dust around its parent star. WASP-39 b’s chemical inventory indicates a history of mergers and mergers of smaller bodies called planetesimals to eventually create a giant planet.

The abundance of sulfur (relative to) hydrogen indicates that the planet has likely experienced a large accumulation of minor planetesimals. [deze ingrediënten] “The data also indicates that oxygen far outweighs carbon in the atmosphere,” said Kazumasa Ohno, an exoplanet researcher at the University of California, Santa Cruz who worked on Webb’s data. This may indicate that WASP-39 b originally formed far from the star. Central.” By dissecting an exoplanet’s atmosphere with such precision, Webb’s instruments have far exceeded scientists’ expectations.

“We will be able to see the big picture of exoplanet atmospheres,” said Laura Flagg, a researcher at Cornell University and a member of the international team. “It’s very exciting to know that everything is going to be rewritten. And that’s one of the most beautiful parts of being a scientist.”

source: NASA