NASA just reported that their Cassini spacecraft has found what appears to be giant dust storms in the equatorial regions of Saturn's moon Titan. The discovery was detailed in a paper published on September 24 in Nature Geoscience. This makes Titan the third body in our solar system, aside from Earth and Mars, where dust storms have been seen.
An astronomer at the Université Paris Diderot, Sebastien Rodriguez, explained, "Titan is a very active moon. We already know that about its geology and exotic hydrocarbon cycle. Now we can add another analogy with Earth and Mars: the active dust cycle, in which organic dust can be raised from large dune fields around Titan's equator."
Researchers say Titan is very similar to Earth in some ways. It's actually the only moon in the solar system with a substantial atmosphere and it's the only celestial body other than Earth where stable surface liquid is known to exist. Titan also has seasons much like the Earth. During its equinox, massive clouds form in the tropical regions and cause strong methane storms. How does Titan have methane storms? On our home planet, seas, lakes, and rivers are full of water. But on Titan, they are mostly filled with methane and ethane. This causes hydrocarbon molecules to evaporate, turn into clouds, and rain back down.
Rodrigues and other researchers spotted three clouds on Titan that they thought were methane clouds in 2009 but after an investigation, they learned they were completely different.
"From what we know about cloud formation on Titan, we can say that such methane clouds in this area and in this time of year are not physically possible. The convective methane clouds that can develop in this area and during this period of time would contain huge droplets and must be at a very high altitude -- much higher than the 6 miles that modeling tells us the new features are located."
They determined the features must have been atmospheric but also close to the surface. The only remaining explanation was that they were actually dust clouds raised from the dunes.
Rodriguez explained, "We believe that the Huygens Probe, which landed on the surface of Titan in January 2005, raised a small amount of organic dust upon arrival due to its powerful aerodynamic wake. But what we spotted here with Cassini is at a much larger scale. The near-surface wind speeds required to raise such an amount of dust as we see in these dust storms would have to be very strong -- about five times as strong as the average wind speeds estimated by the Huygens measurements near the surface and with climate models."
According to Fox News, these dust storms indicate that sand on Titan can be moved and that the giant dunes covering the equatorial regions are constantly changing and still active.