NASA scientists have found a new interesting subject to study about exoplanets, worlds beyond our solar system. Thanks to the archival data from the now-retired Spitzer Space Telescope, astronomers have zeroed in on clouds of exoplanets. While clouds on some planets are abundant in ammonia and ammonium hydrosulfide, others have clouds composed of silicates, the family of rock-forming minerals that make up over 90% of Earth’s crust.
When astronaut Cooper heads down on Dr. Mann’s planet beyond the wormhole, his spacecraft hits the clouds that are frozen, it was a fictional world created by Christopher Nolan that existed in another galaxy. A new study reveals there could be worlds with unique cloud properties even like the one on Dr. Mann’s planet.
A study of archival data generated over the years by the now-retired Spitzer telescope reveals a common trait among exotic clouds. Beyond Earth, where clouds are made up of water vapour, there are worlds with unique chemical compositions below the atmosphere. There are clouds made up of sand.
A new study published in the journal Monthly Notices of the Royal Astronomical Society sheds light on worlds outside our solar system, where clouds composed of silicates exist, the family of rock-forming minerals that make up over 90% of Earth’s crust. The findings reveal the temperature range at which silicate clouds can form and are visible at the top of a distant planet’s atmosphere.
“Understanding the atmospheres of brown dwarfs and planets where silicate clouds can form can also help us understand what we would see in the atmosphere of a planet that’s closer in size and temperature to Earth,” said Stanimir Metchev, a professor of exoplanet studies at Western University in London, Ontario, and co-author of the study said in a statement.
The findings have been taken from the observations by Nasa’s retired Spitzer Space Telescope of brown dwarf’s celestial bodies that fall in between planets and stars but it fits into a more general understanding of how planetary atmospheres work.
Floating in one of these clouds would feel like being in a sandstorm, says planetary scientist Mark Marley of the University of Arizona in Tucson, who was involved in one of those early discoveries. “If you could take a scoop out of it and bring it home, you would have hot sand.”
Scientists have said that the process of formation of these clouds involves heating the key ingredient until it becomes a vapor. Under the right conditions, that ingredient could be a variety of things, including water, ammonia, salt, or sulfur. Then it is cooled, just enough for it to condense. Since they require insane heat, silicate clouds are visible only on hot worlds, such as the brown dwarfs used for this study and some planets outside our solar system.
“Although they form like stars, brown dwarfs aren’t massive enough to kick-start fusion, the process that causes stars to shine. Many brown dwarfs have atmospheres almost indistinguishable from those of gas-dominated planets, such as Jupiter, so they can be used as a proxy for those planets,” Nasa said.
The observations were made during the first six years of the Spitzer telescope and with the beginning of science operations by the James Webb Telescope, these findings could further be refined. The planets observed fell in the temperature range of 1000 degrees Celsius.
“We had to dig through the Spitzer data to find these brown dwarfs where there was some indication of silicate clouds, and we really didn’t know what we would find. We were very surprised at how strong the conclusion was once we had the right data to analyze,” Genaro Suárez, a postdoctoral researcher at Western University and lead author of the new study said.
