Saturn’s largest moon could see 10-foot waves from a tiny breeze
Titan is by far the largest of Saturn’s 292 known moons. It is also the only other cosmic body, besides Earth, that hosts stagnant liquid similar to our oceans in our solar system. But don’t necessarily expect calm conditions. According to a new modeling system detailed in the Geophysical Research Journal: Planetsthe slightest gust of wind on Titan could generate enormous breaking waves on seas of hydrocarbons.
Although there are endless fascinating places in our solar system, Titan remains one of the most intriguing. It is nearly 50% larger and 80% more massive than Earth’s Moon, making it even larger than the planet Mercury. Titan is also packed with prebiotic compounds, meaning it’s one of the top contenders for hosting ocean life beneath its icy shell.
Even though its average surface temperature of -296.59 degrees Fahrenheit ensures a complete absence of running water, there are still rivers and seas full of light hydrocarbons such as ethane and methane. Astronomers have long suspected that these large masses of liquid generate waves that regularly carve coastlines and shape landscapes, but Titan’s thick atmosphere and distance from Earth make this confirmation difficult.
Scientists may still lack visual confirmation of the Moon’s waves, but they can now get a better idea of ​​their fluid dynamics thanks to a new modeling system from the Massachusetts Institute of Technology (MIT) and Woods Hole Oceanographic Institution (WHOI). Aptly named PlanetWaves, the free simulator indicates that unlike Earth, the smallest breeze would easily give rise to 10-foot waves thanks to Titan’s unique surface.
“On Earth, we become accustomed to certain wave dynamics,” Andrew Ashton, study co-author and geophysicist at WHOI, said in a statement. “But with this model we can see how waves behave on planets with different liquids, atmospheres and gravity, which can somehow challenge our intuition.”
Waves on Titan vs waves on Earth
Previous research has largely focused on predicting the impact of a planet’s gravity on waves. As MIT planetary scientist Una Schneck explains, their team’s model is the first to include other important compositional factors such as a liquid’s surface tension, viscosity, and density. And when it comes to Titan’s liquid, the results would be difficult to understand if seen firsthand.
“It looks like big waves moving in slow motion,” Schneck said. “If you stood on the edge of this lake, you might only feel a gentle breeze, but you would see these huge waves flowing toward you, which is not what we would expect on Earth.”
Gravity also plays an important role in allowing or preventing waves. In addition to Titan, the study authors tested PlanetWaves under conditions once observed on ancient Mars, as well as on three exoplanets far beyond our solar system. In each case, the unique factors of the location create very different situations.
“Cool super-Earth” LHS1140b may contain water, but its strong gravity would hamper large waves without significant wind gusts. Meanwhile, the sulfuric acid lakes of the Venus-like exoplanet Kepler 1649b require even stronger wind speeds. However, the exoplanet 55-Cancri e is the most tenacious of all the simulated planets. Its powerful gravity and oceans of molten lava would need hurricane-like conditions to create even the smallest waves.
PlanetWaves is much more than a new simulator. Calculating how fluids behave on distant planets and moons could help engineers build new spacecraft and probes. If all goes according to plan, the Artemis program is expected to establish the first long-term human presence on the Moon sometime in 2028. What comes next is anyone’s guess, but researchers are preparing to go with the flow.
“Imagine a completely still lake,” Ashton said. “We’re trying to determine the first puff that will produce those first little ripples, all the way up to a full ocean wave.”
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