Source: Al Arabiya
Thursday, November 24, 2022
Images captured by NASA’s James Webb Telescope reveal new information about the molecular and chemical profile of a distant exoplanet named WASP-39b.
WASP-39b is an exoplanet, which means that it is a planet that is outside our solar system, some 700 light years away from our planet.
Although Webb and other space telescopes previously revealed some of the isolated ingredients of this broiling planet’s atmosphere, the new readings from Webb provided more information on atoms, molecules, and even signs of active chemistry and clouds.
The latest data also suggests that these clouds might appear broken up from up-close rather than a single, uniform blanket over the planet.
Similar to Saturn in mass and Jupiter in size, WASP-39b is made of gas and is extremely hot. The planet has been the subject of great fascination among scientists since it was first discovered almost a decade ago.
The telescope’s array of highly sensitive instruments was trained on the atmosphere of WASP-39b, a “hot Saturn” – a planet about as massive as Saturn but in an orbit tighter than Mercury.
“We observed the exoplanet with multiple instruments that, together, provide a broad swath of the infrared spectrum and a panoply of chemical fingerprints inaccessible until [this mission],” an astronomer at the University of California, Santa Cruz, who contributed to and helped coordinate the new research, Natalie Batalha, said in a statement carried by NASA on Tuesday.
“Data like these are a game changer.”
Among the unprecedented findings was the first-ever detection of sulfur dioxide (SO2) in an exoplanet atmosphere, a molecule produced from chemical reactions triggered by high-energy light from the planet’s parent star. On Earth, the protective ozone layer in the upper atmosphere is created in a similar way.
“This is the first time we see concrete evidence of photochemistry – chemical reactions initiated by energetic stellar light – on exoplanets,” 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-39b’s atmosphere.
“I see this as a really promising outlook for advancing our understanding of exoplanet atmospheres with [this mission].”
To capture the broad spectrum of the molecules present in the exoplanet’s atmosphere, an international team of hundreds of scientists independently analyzed the data picked up by Webb.
To see light from WASP-39b, the telescope tracked the planet as it passed in front of its star, allowing some of the star’s light to filter through the planet’s atmosphere.
Different types of chemicals in the atmosphere absorb different colors of the starlight spectrum, so astronomers are able to determine which molecules are present just by identifying which colors are missing from the spectrum.
Webb is able to pick up chemical fingerprints that cannot be detected in visible lift as it views the universe in infrared light.
The telescope picked up on sodium, potassium, and water vapor in the exoplanet’s atmosphere, confirming previous space and ground-based observations and finding additional fingerprints of water, at these longer wavelengths for the first time.
It also picked up on carbon dioxide at higher resolution, providing twice as much data as reported from its previous observations.
Carbon monoxide was also detected but obvious signatures of both methane and hydrogen sulfide were absent from the data. If present, these molecules occur at very low levels, NASA said.
The findings are detailed in a set of five new scientific papers, three of which are in press and two of which are under review.
“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 UK’s University of Bristol, who investigates exoplanet atmospheres.
WASP-39 b’s chemical inventory suggests a history of smashups and mergers of smaller bodies called planetesimals to create an eventual goliath of a planet.