Forget Cats And Dogs, NASA's Webb Telescope Found A Planet Where It Rains Sand

Planet with clouds made of sand.
European astronomers using data gleaned from the James Webb Space Telescope (JWST) have found an exoplanet that not only has water vapor and sulfur dioxide in its atmosphere, but also silicate clouds that eventually falls as sand rain. Not so great if you left your car parked outside.

JWST has brought us many wonderous observations of objects from the farther reaches of the universe, as well as other celestial objects closer to Earth. Recently, data from an object discovered in 2017 caught the attention of a group of European astronomers based at the KU Leuven Institute of Astronomy in Belgium.

Located some 212 light-years away from us, WASP-107b—an exoplanet previously known for its "puffy" appearance—has been found to actually have sand as part of its cloud system, among other things. The team thinks that the sand cloud atmosphere forms the same way as water vapor-based clouds here on Earth. When sand rain droplets fall towards the surface, the planet's hot layers evaporate the droplets into silicate vapor, and then recondense into clouds to repeat the cycle. Yes, consider our minds blown. 

What's more, WASP-107b also contains sulfur dioxide (which is similar to the smell of rotten eggs or a struck match) and water vapor. While it's too early to tell how the water vapor factors into the overall atmospheric cycle versus sand, the significant presence of sulfur dioxide could indicate that there might be a water-sulfuric acid evaporative cycle occurring on WASP-107b.

The "puffy" exoplanet is called as such because of its low density. It is roughly the size of Jupiter with merely 12 percent of its mass. WASP-107b orbits its sun (that is slightly smaller and cooler than our own) once every 5.7 days and surface temperatures exceeding 900 degrees Fahrenheit. 


Even though its sun emits a smaller fraction of high-energy light protons, JWST's Mid-Infrared Instrument (MIRI) spectograph was able to read the photons as they penetrate deep into WASP-107b's low density atmosphere. In a release statement, Leen Decin, lead author of the research said, "The discovery of clouds of sand, water, and sulfur dioxide on this fluffy exoplanet … is a pivotal milestone. It reshapes our understanding of planetary formation and evolution, shedding new light on our own solar system."

Top image credit: LUCA School of Arts, Belgium/ Klaas Verpoest (visuals), Johan Van Looveren (typography). Science: Achrène Dyrek (CEA and Université Paris Cité, France), Michiel Min (SRON, the Netherlands), Leen Decin (KU Leuven, Belgium) / European MIRI EXO GTO team / ESA / NASA