NASA’s James Webb Space Telescope has made a remarkable discovery: a planet nearly 700 light-years away where clouds are made of rock — and they vanish every evening.
The planet, known as WASP-94A b, is what astronomers call a “Hot Jupiter” — a massive gas giant that orbits very close to its star, making it incredibly hot. Its dayside reaches temperatures above 1,000 degrees Celsius.
Using the Webb telescope, scientists from Johns Hopkins University studied what happens in the planet’s atmosphere as it passed in front of its star. What they found was surprising.
Every morning, thick clouds made from a rocky mineral called magnesium silicate build up on the cooler side of the planet. But as those clouds drift into the scorching dayside, the intense heat causes them to simply dissolve. By evening, the skies on that side are completely clear.
On Earth, clouds are made of water droplets — but on this world, they are made from the same minerals that form rocks and sand here at home. The whole cycle repeats every day.
Scientists say this discovery gives them one of the clearest looks yet at how weather works on planets outside our solar system. The results were published in the journal Science this week.
