Skip to main content

James Webb spots carbon dioxide in exoplanet atmosphere for first time

Researchers using the James Webb Space Telescope have detected carbon dioxide in an exoplanet atmosphere for the first time, demonstrating how using the new space telescope will help us to learn about far-off planets and even to find potentially habitable planets outside our solar system.

The planet in question, called WASP-39 b, is a gas giant orbiting a sun-like star and is located around 700 light-years away. Its mass if just a quarter of the mass of Jupiter, but its diameter is 1.3 times Jupiter’s, so it is not dense and is very puffy. As it orbits very close to its star, with a year there lasting just over four Earth days, it has very high surface temperatures and is a type of planet called a hot Jupiter.

This is an illustration (artist’s impression) showing what the exoplanet WASP-39 b could look like, based on current understanding of the planet.
This is an illustration (artist’s impression) showing what the exoplanet WASP-39 b could look like, based on current understanding of the planet. NASA, ESA, CSA, and J. Olmsted (STScI)

The research team was able to see into WASP-39 b’s atmosphere using Webb’s NIRSpec instrument. This spectrometer splits light into different wavelengths to see which wavelengths have been absorbed — and that indicates the composition of the object. When looking at the light coming from the host star when the planet passed in front of it, the researchers could get data on its atmosphere using a method called transmission spectroscopy.

The results show a clear blocking of light between the 4.1 and 4.6-micron wavelengths, which indicates the presence of carbon dioxide. “As soon as the data appeared on my screen, the whopping carbon dioxide feature grabbed me,” said one of the researchers, Zafar Rustamkulov of Johns Hopkins University, in a statement. This is the first time that carbon dioxide has been identified in an exoplanet atmosphere. “It was a special moment, crossing an important threshold in exoplanet sciences.”

Learning about exoplanet atmospheres helps to understand how the planet evolved. And as well as helping scientists to learn about this particular planet, the results are an exciting demonstration of how James Webb can help us learn about other exoplanets in the future. “Seeing the data for the first time was like reading a poem in its entirety, when before we only had every third word,” said team member Laura Kreidberg of the Max Planck Institute for Astronomy. “These first results are just the beginning; the Early Release Science data have shown that Webb performs beautifully, and smaller and cooler exoplanets (more like our own Earth) are within its reach.”

The research will be published in the journal Nature.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
James Webb captures the rarely-seen rings around Uranus
This zoomed-in image of Uranus, captured by Webb’s Near-Infrared Camera (NIRCam) on 6 February 2023, reveals stunning views of the planet’s rings. The planet displays a blue hue in this representative-colour image, made by combining data from two filters (F140M, F300M) at 1.4 and 3.0 microns, shown here as blue and orange, respectively.

The James Webb Space Telescope spends much of its time peering out into distant regions of space searching for some of the earliest galaxies to exist, but it also occasionally turns its sights onto targets a little closer to home. Following up on its image of Neptune released last year, astronomers using Webb have just released a brand-new image of Uranus as you've never seen it before.

As Webb looks in the infrared wavelength, unlike telescopes like Hubble which look in the visible light spectrum, its image of Uranus picks out some features of the planet which are hard to see otherwise like its dusty rings. Uranus' rings are almost invisible in the optical wavelength, but in this new image, they stand out proudly.

Read more
James Webb spots exoplanet with gritty clouds of sand floating in its atmosphere
This illustration conceptualises the swirling clouds identified by the James Webb Space Telescope in the atmosphere of the exoplanet VHS 1256 b. The planet is about 40 light-years away and orbits two stars that are locked in their own tight rotation. Its clouds, which are filled with silicate dust, are constantly rising, mixing, and moving during its 22-hour day.

One of the most exciting things about the James Webb Space Telescope is that not only can it detect exoplanets, but it can even peer into their atmospheres to see what they are composed of. Understanding exoplanet atmospheres will help us to find potentially habitable worlds, but it will also turn up some fascinating oddities -- like a recent finding of an exoplanet with an atmosphere full of gritty, sand clouds.

Exoplanet VHS 1256 b, around 40 light-years away, has a complex and dynamic atmosphere that shows considerable changes over a 22-hour day. Not only does the atmosphere show evidence of commonly observed chemicals like water, methane, and carbon monoxide, but it also appears to be dotted with clouds made up of silicate grains.

Read more
Astronomers share early images from James Webb’s galaxy survey
Images of four example galaxies selected from the first epoch of COSMOS-Web NIRCam observations, highlighting the range of structures that can be seen. In the upper left is a barred spiral galaxy; in the upper right is an example of a gravitational lens, where the mass of the central galaxy is causing the light from a distant galaxy to be stretched into arcs; on the lower left is nearby galaxy displaying shells of material, suggesting it merged with another galaxy in its past; on the lower right is a barred spiral galaxy with several clumps of active star formation.

One of the major aims of the James Webb Space Telescope is to observe some of the earliest galaxies in the universe, and to do that it needs to be able to see extremely distant objects. But looking at a particular very old galaxy in detail is only half of the problem. To truly understand the earliest stages of the universe, astronomers also need to see how these very old galaxies are distributed so they can understand the large-scale structure of the universe.

That's the aim of the COSMOS-Web program, which is using James Webb to survey a wide area of the sky and look for these rare, ancient galaxies. It aims to study up to 1 million galaxies during over 255 hours of observing time, using both Webb's near-infrared camera (NIRCam) and its mid-infrared instrument (MIRI) camera. While there is still plenty of observing left to do, the researchers in the COSMOS-Web program recently shared some of their first results.

Read more