Skip to main content

James Webb spots exoplanet with gritty clouds of sand floating in its atmosphere

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.

This illustration conceptualizes the swirling clouds identified by the James Webb Space Telescope in the atmosphere of the exoplanet VHS 1256 b.
This illustration conceptualizes 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. NASA, ESA, CSA, J. Olmsted (STScI)

Astronomers were able to get an excellent view of the planet because instead of orbiting one star like the planets in our solar system, this planet orbits a pair of stars and it takes 10,000 years to complete a full orbit. That means it is far away from the light of its stars, so it is easier for astronomers to see the planet’s relatively dim reflected light.

“VHS 1256 b is about four times farther from its stars than Pluto is from our Sun, which makes it a great target for Webb,” said science team lead Brittany Miles of the University of Arizona in a statement. “That means the planet’s light is not mixed with light from its stars.”

Sand clouds are unusual, but not unheard of when it comes to exoplanets. In this case, the gritty clouds are located up high in the planet’s atmosphere, where temperatures reach an incredible 1,500 degrees Fahrenheit. The planet has low gravity as well, allowing the clouds of both larger and smaller grains to float high in the atmosphere.

“The finer silicate grains in its atmosphere may be more like tiny particles in smoke,” said co-author Beth Biller of the University of Edinburgh. “The larger grains might be more like very hot, very small sand particles.”

The researchers say that although they are excited by their findings, they want to do more research to understand the planet’s atmosphere. “We’ve identified silicates, but a better understanding of which grain sizes and shapes match specific types of clouds is going to take a lot of additional work,” Miles said. “This is not the final word on this planet — it is the beginning of a large-scale modeling effort to fit Webb’s complex data.”

The research is published in The Astrophysical Journal Letters.

Editors' Recommendations

Georgina Torbet
Georgina is the Digital Trends space writer, covering human space exploration, planetary science, and cosmology. She…
James Webb captures stunning image of supernova remnant Cassiopeia A
Cassiopeia A (Cas A) is a supernova remnant located about 11,000 light-years from Earth in the constellation Cassiopeia. It spans approximately 10 light-years. This new image uses data from Webb’s Mid-Infrared Instrument (MIRI) to reveal Cas A in a new light.

A stunning new image from the James Webb Space Telescope shows a famous supernova remnant called Cassiopeia A, or Cas A. When a massive star comes to the end of its life and explodes in a huge outpouring of light and energy called a supernova, it leaves behind a dense core that can become a black hole or a neutron star. But that's not all that remains after a supernova: the explosion can leave its mark on nearby clouds of dust and gas that are formed into intricate structures.

The image of Cas A was taken using Webb's MIRI instrument, which looks in the mid-infrared range. Located 11,000 light-years away, Cassiopeia A is one of the brightest objects in the sky in the radio wavelength, and is also visible in the optical, infrared, and X-ray wavelengths. To see the different features picked up in different wavelengths, you can look at the slider comparison of the Webb infrared image alongside a Hubble visible light image of the same object.

Read more
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
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