Discover a planet with metallic clouds that reflect light like a giant mirror

Observations made by the European Space Agency’s Khufu Space Telescope have revealed the existence of a hypervelocity exoplanet, located 264 light-years from Earth. Named LTT9779b, it surprised the researchers Because it is surrounded by reflective metal clouds that work like a mirror. According to astronomers, it is the brightest planet ever discovered outside our solar system.

High reflection ability

In an article published in the journal Astronomy & Astrophysics, the researchers describe that LTT9779 b, discovered in 2020, has a cloud cover composed primarily of silicates, the same compound found in sand and glass. These clouds also contain mineralswhich makes the planet have a high ability to reflect light.

According to the researchers, LTT9779 b reflects about 80% of the light it receives from its host starA, in an orbit that takes only 19 hours, a record time. Experts claim that, in comparison, in our solar system, Venus is the brightest planet, reflecting about 75% of the sunlight due to a dense layer of clouds. On the other hand, the Earth only reflects about 30% of the sunlight it receives.

The high degree of reflectivity of LTT9779 b surprised the researchers, with the side of the planet facing its star estimated to have a temperature of about 2,000 degrees Celsius. Usually this overheating It would make the planet too hot to form metallic or glass clouds. “It really intrigued us, until we realized we should think of this cloud formation in the same way as the condensation that forms in a shower after a hot shower,” said Vivian Parmentier, a researcher at the Côte d’Azur Observatory in France. , and co-author of the study.

“To steam a bath, you can cool the air until the water vapor condenses, or you can keep the hot water running until clouds form, because the air is too steamy to hold any more,” he explained. int”. In the same way as LTT9779 b They can form mineral clouds even though they are very hot because the atmosphere is saturated with silicates and metal fumes.”