PlanetWaves: A New Model for Predicting Waves on Alien Worlds

Researchers have developed a new model, "PlanetWaves," to simulate wave behavior in liquid bodies on other worlds. Unlike previous models that focused only on planetary gravity, this one also incorporates atmospheric pressure and liquid properties—including density, viscosity, and surface tension.

"That was the big leap with this project," said lead author Una Schneck, regarding the inclusion of these additional factors.

Testing the Model on Earth

The model was calibrated and tested using 20 years of data from buoys on Lake Superior. It successfully and accurately replicated the wave measurements from Earth's largest freshwater lake, validating its approach.

Primary Focus: Saturn's Moon Titan

Titan, Saturn's largest moon, was the primary focus for applying the model. It is the only other known world in our solar system with stable surface liquids.

• Liquid Composition: Titan's liquids are hydrocarbons like methane and ethane, which remain liquid at the moon's frigid surface temperature of -179°C (-290°F).
• Model Prediction: The model suggests that even light winds could generate waves up to 10 feet (3 meters) high on Titan. This is due to the moon's low gravity (just 14% of Earth's) and the lower density of its hydrocarbon liquids compared to water.

"For Titan, the tantalizing thing is that we don't have any direct observations of what these lakes look like. So we don't know for sure what kind of waves might exist there. Now this model gives us an idea," explained researcher Taylor Perron.

Implications for Titan

• Geological Mysteries: Wave erosion might help explain the puzzling absence of river deltas on Titan, despite the presence of numerous rivers and coastlines.
• Future Missions: Understanding wave characteristics would be crucial for designing any future probes intended to float on Titan's lakes.

A Tool for Other Worlds

The PlanetWaves model allows scientists to examine wave behavior on planets with vastly different conditions. As researcher Andrew Ashton noted, it enables the examination of "wave behavior on planets with different liquids, atmospheres, and gravity."

Applications to specific worlds include:

• Mars: The model indicates that as Mars lost atmospheric pressure over time, much stronger winds would have been required to generate waves on its ancient lakes or oceans.
• Exoplanet LHS 1140b: This world's density suggests it could be up to 19% water. However, its stronger gravity would produce smaller waves than on Earth for equivalent wind speeds.
• Exoplanet Kepler-1649b: This Venus-like planet might have lakes of sulfuric acid. The acid's higher density would require strong winds to create any ripples.
• Exoplanet 55 Cancri e: This extremely hot world might have lakes of lava. The model suggests hurricane-force winds (approximately 80 mph) would be needed to create ripples, due to lava's high viscosity and the planet's stronger gravity.