Astronomers see CO2 on exoplanet for first time

Discovery powered by James Webb Space Telescope could yield new clues on composition, formation of planets outside solar system.

Scientists using NASA’s James Webb Space Telescope have captured definitive evidence of carbon dioxide in the atmosphere of a planet beyond our solar system.

The discovery, published in the journal Nature, gives scientists hope the powerful telescope, also known as JWST, will provide new insights on the composition and formation of exoplanets.

“Such a clear detection of carbon dioxide in this planet is exciting because it indicates that we will also be able to detect CO₂ in the atmospheres of smaller, terrestrial planets,” said Mercedes López-Morales of the Center for Astrophysics | Harvard & Smithsonian.

López-Morales is one of two Harvard astrophysicists who worked on the study as part of a team of some 100 scientists. The other, James Kirk, single-handedly performed one of the four analyses the researchers ran on data from the telescope.

“This is the first time we have seen CO₂ in an exoplanet atmosphere, which has incredibly exciting implications for studying carbon and oxygen chemistry in these planets, and in turn on how they form and evolve,” Kirk said.

The carbon dioxide molecules were detected in the atmosphere of “WASP-39 b,” a gas giant orbiting a sun-like star 700 light-years away. Scientists observed the exoplanet on July 10 using the telescope’s Near-Infrared Spectrograph.