The huge gas planet, 1,300 light-years away, is so hot that its clouds are composed of quartz crystals. Studying it could help scientists understand how clouds form in extremely alien environments. The discovery, published Oct. 16 in The Astrophysical Journal Letters, was made by an international team of researchers using the James Webb Space Telescope.

WASP-17b is a Jupiter-like exoplanet that scientists first noticed in 2009. It orbits very close to its star, which heats its atmosphere to an incredible 2,700 degrees Fahrenheit (1,500 degrees Celsius). The planet itself is slightly lighter; Although WASP-17b’s radius is about twice that of Jupiter, its mass is only half that of Jupiter. This makes WASP-17b one of the “puffiest” exoplanets discovered to date.

But recently astronomers discovered that WASP-17b’s puffy clouds seemingly harbor a secret: They’re composed of tiny hard quartz crystals.

“We knew from Hubble observations that WASP-17b’s atmosphere must contain aerosols, which are tiny particles that form clouds or hazes, but we did not expect them to be made of quartz,” said astronomer David Grant from the University of Washington. Bristol. In the statement, it was stated that he was in England and was the first author of the study. “We are so glad!”

These unexpected crystals are the first silicon dioxide particles found in the atmosphere of an exoplanet. The researchers believe that these crystals did not drift from WASP-17b’s surface, unlike small pieces of rock that sometimes drift through Earth’s clouds. Instead, they formed directly in the atmosphere as a result of intense heat and pressure. Based on the way the crystals scatter starlight, the team estimated that each gemstone was about 10 nanometers in diameter; this was less than one millionth the size of an average grain of sand.

It currently remains unclear how widespread these clouds are in the WASP-17b region. The planet is tidally locked, meaning one side is always facing its star and the other side is sideways. On the night side, it is possible for crystals to circulate in the atmosphere and evaporate only during the day.

WASP-17b’s crystal clouds are just one example of an unusual exoplanet feature discovered by JWST; In September, the telescope made news after detecting potential signs of biological life in the atmosphere of exoplanet K2-18 b. Soon the telescope will turn its instruments to other weird and wonderful worlds, and scientists are waiting with bated breath to see what the telescope will see next.