CO2 Spotted in another Solar System by James Webb Telescope
“It’s incontrovertible. It’s there. It’s definitely there,” said planetary scientist and study coauthor Peter Gao of the Carnegie Institution for Science in Washington, D.C., Science News reported.
“There have been hints of carbon dioxide in previous observations, but never confirmed to such an extent,” he added.
The finding, submitted to arXiv.org on August 24, marks the first detailed scientific result published from the new telescope. It also points the way to finding the same greenhouse gas in the atmospheres of smaller, rockier planets that are more like Earth.
The planet, dubbed WASP-39b, is huge and puffy. It’s a bit wider than Jupiter and about as massive as Saturn. And it orbits its star every four Earth days, making it scorching hot. Those features make it a terrible place to search for evidence of extraterrestrial life (SN: 4/19/16). But that combination of puffy atmosphere and frequent passes in front of its star makes it easy to observe, a perfect planet to put the new telescope through its paces.
James Webb, or JWST, launched in December 2021 and released its first images in July 2022 (SN: 7/11/22). For about eight hours in July, the telescope observed starlight that filtered through the planet’s thick atmosphere as the planet crossed between its star and JWST. As it did, molecules of carbon dioxide in the atmosphere absorbed specific wavelengths of that starlight.
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