It's a 'Pivotal Milestone' Courtesy of Webb Telescope

The James Webb Space Telescope has revealed details of an "absolutely hostile" planet where it rains, not water, but particles of silicate sand, which whip around at speeds of a couple of miles per second. The gas giant Wasp-107b, some 200 light years away in the Virgo constellation, is nicknamed the "candy floss" planet because of what experts describe as its "fluffy" structure, per the Guardian. Discovered in 2017 when astronomers noticed a flickering in the light of its host star indicating a planet in orbit, Wasp-107b is nearly as large as Jupiter but has a similar mass as the smaller Neptune. Its low density "enables astronomers to look roughly 50 times deeper into its atmosphere compared to the depth of exploration achieved for a solar-system giant like Jupiter," per a release.

Undressed by NASA's James Webb telescope, Wasp-107b was found to have "something akin to Earth's water cycle" but "with sand cycling between solid and gaseous states" as it travels from the lower levels of the atmosphere, with temperatures around 1,000 degrees Celsius, to the higher, cooler levels, around 500 degrees Celsius, per the Guardian. Here, clouds of tiny specks of silicate form before unleashing a downpour. "The clouds would be like a hazy dust," Leen Decin of Belgium's KU Leuven research university, lead author of the study published Wednesday in Nature, tells the Guardian. "And these sand particles are streaming around at extremely high velocity."

The atmosphere also shows evidence of water vapor and sulfur dioxide, known as the scent of burnt matches, per the release. It notes the presence of So2 came as "a major surprise." The exoplanet's host star, a bit cooler than our own Sun, "emits a relatively small fraction of high-energy photons" needed to trigger the chemical reactions that produce sulfur dioxide. However, these photons were found to "reach deep into the planet's atmosphere thanks to its fluffy nature." It's the first time astronomers have definitively identified the chemical composition of an exoplanet's clouds, per Earth.com, and marks what Decin describes as "a pivotal milestone," per the release. "It reshapes our understanding of planetary formation and evolution, shedding new light on our own Solar System." (More exoplanet stories.)