James Webb Space Telescope: Sand Rains on Exoplanet WASP

Highlights: James Webb Space Telescope: Sand Rains on Exoplanet WASP-107b. For the first time, scientists have used the James Webb telescope to take a sharp look at the atmosphere of an exoplanet. They discovered similarities with Earth – but also raindrops made of sand in gigantic heat. The researchers did not find any evidence of methane, which was discovered in previous investigations. On the other hand, the discovery of sulphur dioxide, the smell of burnt matches, was a surprise.

For the first time, scientists have used the James Webb telescope to take a sharp look at the atmosphere of an exoplanet. They discovered similarities with Earth – but also raindrops made of sand in gigantic heat.

Enlarge image

Planet in the Sand Rain: Illustration by WASP-107b

Photo: Illustration: LUCA School of Arts / Klaas Verpoest / Johan Van LooverenM; Science: Achrène Dyrek / Michiel Min / Leen Decin / European MIRI EXO GTO Team / ESA / NASA

There are all kinds of strange worlds in space. Ever since the study of exoplanets, i.e. planets orbiting a star other than our Sun, gained momentum, astronomers have already discovered the most unusual places. For example, planets made of diamonds. Or those on which it rains molten iron.

Many of these discoveries were only possible because the observation technology for them was constantly improved. The new data from the exoplanet WASP-107b, for example, were collected with the James Webb Space Telescope. They not only show evidence of water vapour and sulphur dioxide, but also special clouds: it occasionally rains sand there, astronomers report in a study in the journal "Nature".

WASP-107b was discovered back in 2017. The gaseous exoplanet orbits a star that is slightly cooler and less massive than our Sun. It has about the mass of Neptune, but is about the circumference of the much larger Jupiter, and has therefore become known as the "cotton candy" planet. It is downright fluffy, the researchers report.

As a result, the experts were able to use instruments from the James Webb Space Telescope (JWST) to look about 50 times deeper into its atmosphere than would be the case with Jupiter. The signals for spectral analysis, which show the chemical elements on the planet due to different wavelengths of light, are more pronounced in less dense atmospheres.

Milestone in exo-atmospheric research

In this way, the researchers were able to track down clouds of water vapour, sulphur dioxide and silicate. Clouds are also suspected on other exoplanets. But it is the first time that the chemical composition of these clouds has been definitively determined.

"The discovery of clouds of sand, water and sulfur dioxide on this fluffy exoplanet by JWST's Miri instrument is a crucial milestone. It changes our understanding of planet formation and evolution and sheds new light on our own solar system," says Leen Decin of Belgium's KU Leuven, one of the lead authors of the study.

The researchers did not find any evidence of methane, which was discovered in previous investigations. On the other hand, the discovery of sulphur dioxide, the smell of burnt matches, was a surprise.

It is possible that sulfur dioxide is formed because the light from the star of WASP-107b can easily penetrate its atmosphere and therefore travels far towards the surface – this favors the formation of the gas, according to the researchers.

As the study also shows, the silicate sand clouds rain down, the cloud cycle is similar to that on Earth – but with droplets of sand instead of water. The temperatures are also different. When it rains sand high up in the atmosphere of the celestial body, it becomes around 500 degrees Celsius.

Joe

James Webb Space Telescope: Sand Rains on Exoplanet WASP

Milestone in exo-atmospheric research

Trends 24h

Latest