Mystery solved? Scientists theorize why lakes and rivers on Titan don't have waves
Saturday, July 27, 2013, 1:11 - Scientists believe they may finally understand why lakes and rivers on Saturn's moon Titan have no waves - but the exact reason is still up for debate.
For years scientists at NASA have known about strange lakes and rivers on Saturn's moon Titan, but could never find any waves like those seen on Earth.
The moon has always been of particular interest to researchers because aside from Earth, it's the only other object with clear evidence showing stable bodies of surface liquid.
The first pictures showing liquid formations on Titan emerged in 2004 when NASA’s Cassini spacecraft arrived in the Saturn system.
Further evidence of liquid was discovered when The European Space Agency's Huygens probe plowed into Titan’s mud.
One problem with Earth comparisons were that temperatures on the moon approached -180 Celsius, freezing any water on the surface.
Upon further investigation, scientists concluded Titan's lakes were a combination of liquid methane, ethane, and other elements with low freezing points, but they couldn't understand the still nature of the liquid.
On Earth, conditions such as wind, rain, tides and tremors move water in all directions but there was nothing on Titan.
Titan does have wind and rain, its vast sand dunes are an example of that.
Alex Hayes, a planetary scientist at Cornell University who works on the Cassini radar, calculated the required wind speed to generate waves on Titan.
If you take into account the moon's gravity (one-seventh that of Earth), thick atmosphere, and nature of liquids found on its surface, gusts just over 3 km/h would be sufficient to generate waves.
Scientists believe that three reasons exist for the anomaly, either the lakes are covered in a tar-like substance, are frozen, or simply the winds have not been strong enough to generate movement.
Hayes doesn't believe freezing is a possibility because there has been evidence of rainfall and surface temperatures well above the freezing point of methane.
A tar substance would dampen any motion on lakes and rivers and is a strong possibility.
A better understanding of the fluids found on the surface could occur in 2017, when the moon nears its summer solstice.
Currently it's winter in Titan's northern hemisphere, meaning the air is colder, thicker, and less likely to generate waves.
The discovery of waves would be important in determining the chemical composition of Titan's lakes.
It would allow scientists to explore further the possibility of life on surfaces similar to Earth, but with very different atmospheric conditions.