In a first,James Webb Space Telescope reveals distant gassy atmosphere is filled with carbon dioxide

[Judi Lynn]

Scientists used transmission of light to determine the makeup of the gas giant's atmosphere.

BY LAURA BAISAS | PUBLISHED AUG 26, 2022 11:00 AM

NASA’s James Webb Space Telescope (JWST) continues its sizzling summer of scientific discovery, finding the first clear evidence of carbon dioxide in the atmosphere of an exoplanet. The findings have been accepted for publication in the journal Nature. Extrasolar planets, or exoplanets, are any planet outside of our solar system. Most of them orbit other stars the way Earth orbits the sun, but some free-floating exoplanets (aka rogue planets) orbit a galactic center, untethered to any other stars.

This new finding means that the groundbreaking JWST may be able to detect and measure key molecules like carbon dioxide in the thinner atmospheres of smaller rocky planets in the future. This kind of data gives scientists insight into the formation, composition, and evolution of the galaxy’s planets.

Exoplanet WASP-39b was first discovered in 2011. Seven years later, NASA’s Hubble and Spitzer space telescopes detected water vapor, sodium, and potassium in WASP-39b’s atmosphere, offering a glimpse at what’s going on around the planet. In 2022, it became the first exoplanet to be studied by JWST.

Spinning about 700 light-years away from Earth, WASP-39b is a hot gas giant with a mass about the same as Saturn, but a diameter about 1.3 larger than Jupiter (our solar system’s biggest planet). The planet’s puffiness is partially due to the fact that it’s about 1,600 degrees Fahrenheit (900 degrees Celsius), giving it the nickname “hot Saturn.” WASP-39b is in an endless summer because it orbits its home star very closely, unlike the cooler and more compact gas giants in our solar system. It’s so close that it completes a complete orbit of its star, or one “year,” in just over four Earth-days.

More:
https://www.popsci.com/science/carbon-dioxide-exoplanet-atmosphere/

[Judi Lynn]

1. Carbon dioxide detected around alien world for first time

Webb telescope’s first exoplanet result could help scientists understand how planets form
25 AUG 20222:55 PMBYDANIEL CLERY

Astronomers have found carbon dioxide (CO2) in the atmosphere of a Saturn-size planet 700 light-years away—the first unambiguous detection of the gas in a planet beyond the Solar System. The discovery, made by the James Webb Space Telescope, provides clues to how the planet formed. The result also shows just how quickly Webb may identify a spate of other gases, such as methane and ammonia, which could hint at a planet’s potential habitability for life.

Webb is “ushering in this new era of the atmospheric science of exoplanets,” says Nikku Madhusudhan of the University of Cambridge, who was not involved in the study.

The Webb telescope is sensitive to infrared wavelengths of light that are mostly blocked by Earth’s atmosphere. It has already dazzled astronomers with its ability to bring the universe’s most distant stars and galaxies into view.

But the infrared sensitivity is also critical for researchers studying worlds much closer to home, in the Milky Way. When an exoplanet’s orbit takes it in front of its star, some of the starlight passes through the planet’s atmosphere and carries fingerprints of its composition. The atmospheric gases absorb specific wavelengths of light, which show up as dips in brightness when the starlight is spread out into a spectrum.

More:
https://www.science.org/content/article/carbon-dioxide-detected-around-alien-world-first-time