A team of international astronomers using the James Webb Space Telescope (JWST) and its infrared tools observed clouds in the skies of Titan for the first time.
A post on NASA’s Webb blog said finding clouds over Saturn’s largest and most mysterious moon confirms weather models from computer simulations. The observations also match simulations that show clouds forming above Titan’s mid-northern hemisphere during the moon’s summer.
“Titan’s atmosphere is incredibly interesting, not only due to its methane clouds and storms, but also because of what it can tell us about Titan’s past and future—including whether it always had an atmosphere,” NASA’s post said.
Titan fascinates astronomers because of how much is hidden by the moon’s dense, mustard-coloured atmosphere.
What is known is that Titan is the only moon in our Solar System with a dense atmosphere. It is the only known planetary body where rivers, lakes, and seas created rain and carved canyons and valleys. Unlike Earth, the liquid flowing on Titan is made of hydrocarbons that include methane and ethane.
The images from JWST not only provide a look at the clouds in the sky; they also offer a blurry look at Kraken Mare, which is believed to be a methane sea slightly larger than the Caspian Sea. Dark sand dunes can also be seen.
As for the clouds, they were first seen on November 4, and astronomers at the Keck Observatory in Hawaii did follow-up observations on November 6. This second-look at Titan was needed to find out if the clouds moved or changed shape. If so, this would help astronomers understand atmospheric flow on Titan.
As on Earth, clouds do not last long above Titan, and researchers do not know if they witnessed the same clouds on the second day. Jean Lora, an assistant professor of Earth and Planetary Sciences at Yale University, said the observations still confirm Titan has seasonal weather patterns.
Astronomers are still analyzing spectra data collected by Webb. This will provide a composition of Titan’s lower atmosphere and surface. Webb will take another look at Titan in May or June 2023 to study the moon’s complex gases.