Universe: An exoplanet with clouds of sand

The prefix “Exo” is used to describe any planet that is not in our solar system. With new scientific possibilities, more and more exoplanets appear on the search screen. Devices on James Webb TelescopeThe largest reflecting telescope in space. One such instrument is the Mid-Range Infrared Instrument (MIRI) docked at the James Webb Space Telescope.

This is also a kind of virtual laboratory in space that can be used to detect thermal radiation from gas and microscopic dust. The data can be used to draw conclusions about particles in space and examine the composition of fine dust in the universe. In the case of the current analysis, the team around the study’s lead author, Michele Minn SRON Netherlands Institute for Space ResearchMIRI examined the planet “WASP-107b”, which was discovered in 2017 and orbits about 200 light-years from Earth in the “Virgin” star constellation around the star WASP-107, which is slightly cooler and less massive than the Sun.

“Thin” atmosphere.

For the first time, it has become possible to analyze the composition of clouds on an exoplanet, according to a statement issued by the University of Vienna and the University of Leuven on Wednesday, which was also published in the journal Nature. a job They were involved. This was only possible because the planet’s atmosphere is “thin,” according to Manuel Gödel of the University of Vienna, who played a leading role in MIRI’s development from 2003 onwards. WASP-107b is about the mass of Neptune, but about the size of Jupiter.

This combination ensures that the exoplanet’s atmosphere is loosened and allows scientists using MIRI to look into the atmosphere 50 times deeper than is possible with Jupiter. Water vapor, sulfur dioxide (SO2) and silicate clouds can indeed be identified, but not methane (CH4). “First, the absence of methane suggests the possibility of a warm interior atmosphere and provides an exciting insight into the movement of thermal energy in the planet’s atmosphere. Second, the discovery of sulfur dioxide (known for the smell of burning matches) was a big surprise,” the researchers explain. This has now been discovered by The fact is that the celestial body’s host star sends relatively few light particles (photons) and therefore little energy to WASP-107b, but this energy can penetrate deeper inward, which is apparently what causes sulfur dioxide to arise.

Sand clouds and sand rain

However, the data also show that clouds high in the atmosphere partially block out water vapor and sulfur dioxide. However, they are very different from what we know from Earth: they are composed of tiny silicate particles – the main component of sand. “The discovery of clouds of sand, water and sulfur dioxide on this thin exoplanet” is a “critical milestone.” The new findings “change our understanding of planetary formation and evolution and shed new light on our solar system,” Goodale says.

In addition to the sand clouds, there was also evidence of sand rain falling on the distant celestial body. The clouds there cause sand particles to fall at temperatures of about 500 degrees Celsius. “The fact that we see these sand clouds high in the atmosphere must mean that the sand raindrops are evaporating into deeper, hotter layers, and the resulting silicate vapor is efficiently transported to the top, where it condenses back into silicate clouds,” Min explained. Water vapor and cloud cycle on our Earth, but with droplets of sand.