Latest news with #Cassini-Huygens
Yahoo
27-05-2025
- General
- Yahoo
Scientists Puzzled by Mysterious Motion in Atmosphere of Saturn's Moon
Researchers have found that the thick and hazy atmosphere enveloping Saturn's largest moon, Titan, behaves in a very peculiar way. As detailed in a new paper published in The Planetary Science Journal, a team of scientists analyzed 13 years' worth of thermal infrared observations recorded by NASA and the European Space Agency's Cassini-Huygens mission. Their finding: that Titan's atmosphere wobbles like a gyroscope as it shifts with the seasons of its nearly 30 Earth-year cycle, instead of spinning in line with its surface. "The behavior of Titan's atmospheric tilt is very strange," said lead author and University of Bristol postdoctoral researcher Lucy Wright in a statement about the work. "Titan's atmosphere appears to be acting like a gyroscope, stabilizing itself in space." The discovery makes the moon, which has already captured the attention of astronomers for its suspected bodies of liquid and planet-like dimensions — it's larger in diameter than Mercury — an even more intriguing candidate for a closer look, since it appears to have its own, independent climate system. Given the latest discovery, though, scientists are now facing even more riddles about the unusual celestial body. "We think some event in the past may have knocked the atmosphere off its spin axis, causing it to wobble," Wright posited. "Even more intriguingly, we've found that the size of this tilt changes with Titan's seasons." "What's puzzling is how the tilt direction remains fixed in space, rather than being influenced by the Sun or Saturn," coauthor and University of Bristol planetary scientist Nick Teanby added. "That would've given us clues to the cause. Instead, we've got a new mystery on our hands." The findings could influence NASA's upcoming Dragonfly mission, which is tentatively scheduled to launch no sooner than 2028, and will see a massive rotorcraft attempt to descend through Titan's extremely dense atmosphere to explore its surface. It won't be a walk in the park, as it will have to endure temperatures around -300 Fahrenheit while keeping itself airborne with a surface pressure one and a half times that on Earth and winds of up to 20 times faster than the moon's rotation. How the atmosphere "wobbles" on its own could allow scientists to get a better idea of how to keep Dragonfly operational, and where to touch down. The new findings could also have far-reaching implications, forcing us to reevaluate our understanding of the Earth's atmosphere. "The fact that Titan's atmosphere behaves like a spinning top disconnected from its surface raises fascinating questions — not just for Titan, but for understanding atmospheric physics more broadly, including on Earth," said coauthor and NASA Goddard planetary scientist Conor Nixon in the statement. As for the chances that we'll encounter extraterrestrial life on the surface of Titan, astronomers aren't exactly hopeful. In a recent study, scientists concluded that Titan's rivers and lakes of liquid methane make it quite inhospitable to life as we know it. However, they found that a tiny amount of glycine-consuming microbes could, in theory, survive in its oceans. More on Titan: Titan Covered With Fragments of Obliterated Moons, Scientists Say
Yahoo
23-04-2025
- Science
- Yahoo
There's liquid on Titan, Saturn's largest moon. But something's missing and scientists are confused
When you buy through links on our articles, Future and its syndication partners may earn a commission. Scientists have known for a while that Saturn's largest moon, Titan, has rivers and seas of liquid methane on its surface. But it's strangely lacking in deltas, a new study suggests. On Earth, large rivers create deltas with sediment-filled wetlands. Deltas form when the mouth of a river empties into another body of water. Besides Earth, Titan is the only planetary body in our solar system with liquid flowing on the surface. Researchers recently looked for deltas on the big Saturn satellite but came up empty. "We take it for granted that if you have rivers and sediments, you get deltas," study leader Sam Birch, an assistant professor in the Department of Earth, Environmental and Planetary Sciences at Brown University in Rhode Island, said in a statement. "But Titan is weird. It's a playground for studying processes we thought we understood," he added. Related: Titan: Facts about Saturn's largest moon The researchers were hoping to find deltas on Titan, because these landforms feature lots of sediment. The sediment in deltas tends to come from a large area, and deltas gather it in one place. Studying such sediment could reveal insights about Titan's climate and tectonic histories — and perhaps even possible signs of alien life. "It's kind of disappointing as a geomorphologist, because deltas should preserve so much of Titan's history," Birch said. We know that Titan's surface has flowing liquid methane, because NASA's Cassini spacecraft spotted evidence of the stuff on multiple flybys. Cassini used synthetic aperture radar (SAR) to look through Titan's thick atmosphere during these close encounters and found channels and large flat areas that are consistent with large bodies of liquid. But shallow liquid methane is largely transparent in Cassini's SAR data. Scientists have therefore had a hard time studying Titan's coastal features, because it's hard to make out where the coast ends and the sea floor starts. So, Birch's team came up with a computer model that simulates what Cassini's SAR would see when looking at Earth. But the model replaced the water in Earth's rivers and oceans with Titan's liquid methane. "We basically made synthetic SAR images of Earth that assume properties of Titan's liquid instead of Earth's," Birch said. "Once we see SAR images of a landscape we know very well, we can go back to Titan and understand a bit better what we're looking at." Related stories: — The Cassini-Huygens mission: Exploring the Saturn system — The search for alien life — Largest sea on Saturn's mysterious moon Titan could be more than 1,000 feet deep The synthetic SAR images of Earth that they created "resolved large deltas and many other large coastal landscapes," according to the researchers. They say that new analysis of the Cassini SAR data also revealed other mysteries. For example, Titan's coasts appear to have pits of unknown origin deep within lakes and seas, and deep channels cut across the moon's sea floors offer no clue to how they got there. "This is really not what we expected," Birch said. "But Titan does this to us a lot. I think that's what makes it such an engaging place to study." The new study was published in the Journal of Geophysical Research: Planets on March 25.
