Webb provides first molecular and chemical profile of a distant world

The James Webb Space Telescope (JWST) has provided a full menu of atoms, molecules, and even signs of active chemistry and clouds of a distant world - WASP-39 b - that orbits a star some 700 light-years away from us.

This is the first time this broiling planet's molecular and chemical profile has been revealed, thanks to the telescope's array of highly sensitive instruments.

"This is the first time we see concrete evidence of photochemistry – chemical reactions initiated by energetic stellar light – on exoplanets. I see this as a really promising outlook for advancing our understanding of exoplanet atmospheres with [this mission]," said Shang-Min Tsai, a researcher at the University of Oxford in the United Kingdom and lead author of the paper explaining the origin of sulfur dioxide in WASP-39 b's atmosphere.

The unprecedented revelations include the first detection of sulfur dioxide (SO2), a molecule produced from chemical reactions triggered by high-energy light from the planet's parent star, in an exoplanet atmosphere.

Webb also detected other atmospheric constituents including sodium (Na), potassium (K), and water vapor (H2O), confirming previous space and ground-based telescope observations as well as finding additional fingerprints of water, at these longer wavelengths, that haven't been seen before.

Webb tracked WASP-39 b as the planet passed in front of its star, allowing some of the star's light to filter through its atmosphere. The exoplanet's chemical inventory suggests a history of smashups and mergers of smaller bodies called planetesimals to create an eventual goliath of a planet, according to a statement.

"We had predicted what [the telescope] would show us, but it was more precise, more diverse, and more beautiful than I actually believed it would be," said Hannah Wakeford, an astrophysicist at the University of Bristol in the United Kingdom who investigates exoplanet atmospheres.

Webb's latest data gives us the first molecular and chemical profile of a distant world, gas giant WASP-39 b. This bodes well for its ability to probe the atmospheres of small, rocky planets like in the TRAPPIST-1 system: https://t.co/SEnIRYikS0 pic.twitter.com/NeidBgtSJa

— NASA Webb Telescope (@NASAWebb) November 22, 2022

Webb is a mission led by NASA with its partners, ESA (European Space Agency) and CSA (Canadian Space Agency).