The James Webb Telescope offers a never-before-seen view of an exoplanet’s atmosphere

The James Webb Space Telescope has captured a detailed molecular and chemical portrait of the sky of a distant planet, marking a new first for the exoplanet science community.

WASP-39b, also known as Bocaprins, orbits a star some 700 light-years from Earth. It is an exoplanet – a planet outside our solar system – as massive as Saturn. With the difference that it is much closer to its host star, which explains the estimated temperature of nearly 871 degrees Celsius emitted by its gases, as explained by NASA. This “hot Saturn” was one of the first exoplanets the Webb Telescope examined when it began regular scientific operations.

The new readings provide a full breakdown of Bocaprins’ atmosphere, including atoms, molecules, cloud formations and even signs of photochemistry caused by its host star.

“We observed the exoplanet with multiple instruments which together provide a broad band of the infrared spectrum and an array of chemical fingerprints inaccessible until (this mission),” said Natalie Batalha, an astronomer at the University of California who contributed and helped coordinate the new research, in a statement from NASA. “Data like this is a game-changer.”


Bocaprins’ proximity to its host star makes it an ideal subject for studying the connections between stars and their planet. For comparison, the planet is eight times closer to its host star than Mercury is to our sun.

“This is the first time we’ve seen concrete evidence of photochemistry – chemical reactions initiated by energetic starlight – on exoplanets,” said Shang-Min Tsai, a researcher at the University of Oxford in the UK. , in a statement from NASA. “I see this as a really promising prospect for advancing our understanding of the atmospheres of exoplanets.”

Other compounds detected in Bocaprins’ atmosphere include sodium, potassium and water vapour, confirming previous observations made by other space and ground-based telescopes, including the Hubble Space Telescope.

“This is just the beginning”

Having such a comprehensive list of chemical ingredients in an exoplanet’s atmosphere provides insight into how that planet — and possibly others — formed. The diversity of Bocaprins’ chemical inventory suggests that multiple smaller bodies, called planetesimals, merged to create a possible planet goliath, similar in size to the second-largest planet in our solar system.

“This is just the first of many exoplanets that are going to be studied in detail by the JWST (…) We are already getting very interesting results,” Nestor Espinoza, astronomer at the Space Telescope Science Institute, told CNN. . “This is just the beginning.”


“In ten years, astronauts will be living on the moon”, says NASA

The first galaxies may have formed earlier than predicted

Leave a Comment