Titan is one of the largest of Saturn’s moons and has surface liquid, a dense atmosphere — and … More clouds. (Artist’s impression)
getty
According to new data from telescopes, there are clouds in the northern hemisphere of Titan, Saturn’s largest moon. It’s more evidence that Titan, like Earth, has weather — specifically clouds and rainfall — though it’s based not on a cycle of liquid water but on liquid hydrocarbons methane and ethane. Titan is also the only solar system moon with a substantial atmosphere as well as rain, rivers, lakes and seas, according to NASA.
Welcome to the wild world of Titan, the most Earth-like place in the solar system.
What The Webb Telescope Just Saw
Weather on Titan has been probed before by NASA’s Cassini spacecraft and its Huygens lander, as well as with ground-based telescopes like the Keck Observatory in Hawaii. A new research project combining data from the Keck II telescope with new observations using different infrared filters on NASA’s James Webb Space Telescope to probe to varying depths in Titan’s atmosphere has unearthed evidence of cloud convection in the moon’s northern hemisphere for the first time.
That’s precisely where most of Titan’s lakes and seas are located — probably replenished by methane and ethane rain. “We were able to see methane clouds evolving and changing close to Titan’s north pole over multiple days, in the region where large seas and lakes of methane were discovered by the Cassini spacecraft,” said Conor Nixon of NASA’s Goddard Space Flight Center in Greenbelt, Maryland, lead author of a paper published in Nature Astronomy. “This enables us to understand better Titan’s climate cycle, how the methane clouds may generate rain and replenish methane evaporated from the lakes.”
These images of Titan were taken by NASA’s James Webb Space Telescope on July 11, 2023 (top row) and … More the ground-based W.M. Keck Observatories on July 14, 2023 (bottom row). They show methane clouds (denoted by the white arrows) appearing at different altitudes in Titan’s northern hemisphere.
NASA, ESA, CSA, STScI, Keck Observatory
What It’s Like On Titan
Titan has a 98% nitrogen and 2% methane atmosphere. It has liquid methane rain, lakes, oceans, and other stuff. Those bodies of liquid carve out shorelines, valleys, mountain ridges, icy boulders, mesas and dunes. Satellites have seen all of those physical features before — and now they’ve seen clouds, evidence for the methane cycle. “On Titan, methane is a consumable,” said Nixon. “It’s possible that it is being constantly resupplied and fizzing out of the crust and interior over billions of years. If not, eventually, it will all be gone, and Titan will become a mostly airless world of dust and dunes.”
It’s extremely cold on Titan — about -290 degrees Fahrenheit (-180 degrees Celsius). Titan’s gravity is 14% of the Earth’s, meaning it would be possible for astronauts to fly.
On its surface, Titan also has complex organic compounds formed from methane and nitrogen in the moon’s atmosphere. These compounds could contain the prebiotic chemistry of the building blocks of life. Webb also found a key carbon-containing molecule in Titan’s complex atmosphere.
Artist’s concept of Dragonfly soaring over the dunes of Saturn’s moon Titan.
NASA/Johns Hopkins APL/Steve Gribben
Huygens At Titan
NASA’s flagship Cassini probe flew 600 miles above Titan during its 2004-2017 mission, sending back data on its incredible landscape. It also deposited a probe called Huygens, which descended to Titan’s surface on Jan. 14, 2005. It shot a historic time-lapse video during its 2 hours 27 minutes parachute journey to the surface. Huygens instantly became, and remains the farthest spacecraft from Earth on the surface of another world.
NASA hasn’t been back to Titan since, but it now has exciting plans. Its Dragonfly mission will launch in July 2028 atop a SpaceX Falcon Heavy rocket and reach the distant moon in 2034. The mission will have a drone-like rotorcraft tour Titan to analyze what’s on its surface.
Wishing you clear skies and wide eyes.