Data from the James Webb Space Telescope shows a huge cloud of sand rising above the fluffy Jupiter-sized planet WASP-107b.
In 2017, astronomers discovered this unique planet in the constellation Virgo, about 200 light-years from Earth. WASP-107b has a similar mass to Neptune, but its radius is much larger and closer to Jupiter, making it much less dense than other gas giants, about the same density as cotton candy.This is why it looks fluffy, he says. Leanne Dessin At the University of Leuven, Belgium.
“In fact, this fluffy planet is one of the least dense we’ve ever seen,” she says. “This allows us to look really deep into the atmosphere of that planet.”
Using the James Webb Space Telescope’s mid-infrared instrument, Dechin and her colleagues are currently peering into WASP-107b.
They discovered that two of the main components of that atmosphere are sulfur dioxide and water vapor. Deschin said sulfur dioxide had previously been detected in hot gas giants with an average temperature of 1,200 Kelvin (927 degrees Celsius), but finding it in WASP-107b, which has an average temperature of nearly 700 K (427 degrees Celsius), was considered surprising. It’s too cold to produce large amounts of sulfur dioxide.
One possible explanation for its existence is that more ultraviolet light from its host star, WASP-107, could penetrate the planet due to its relatively low density, triggering chemical reactions that form compounds. That may be the case.
Perhaps even stranger, Deschin and her colleagues discovered clouds made of tiny silicate particles, a substance that forms sand, in the planet’s upper atmosphere. Researchers believe that in deeper, hotter parts of Earth’s atmosphere, gaseous silicates can rise to cooler areas and condense to form clouds, similar to what happens with water on Earth. I’m sure it’s going to rain like that.
“This is the first time we’ve determined the composition of an extrasystem cloud,” Dechin said.
The discovery could improve models of planet formation and evolution. “We understand things based on our own experiences on Earth, but that’s a very limited perspective,” she says. “Understanding the mechanics and chemistry of exoplanets can really enhance our view of the universe.”