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Phoenix666 writes:

The aptly named Titan, Saturn's largest moon, is remarkably Earth-like. Its diameter is only about 40% that of our planet, but Titan's nitrogen-rich, dense atmosphere and the geological activity at the moon's surface make comparisons between the two bodies inevitable.

This image, taken with the radar on the Cassini spacecraft, shows just how similar the features in Titan's surface are to Earth's landforms.

Aside from Earth, Titan is the only other body where we have found evidence of active erosion on a large scale. There are seas, lakes and rivers filled with liquid hydrocarbons – mainly methane and some ethane – that etch the moon's surface, in much the same way water erodes Earth's.

A striking example is Vid Flumina, the Nile-like, branching river system visible on the upper-left quadrant of the image. The river, in the moon's north polar region, flows into Ligeia Mare, a methane-rich sea that appears as a dark patch on the right side of the image.

Researchers in Italy and the US analysed Cassini radar observations from May 2013 and recently revealed that the narrow channels that branch off Vid Flumina are deep, steep-sided canyons filled with flowing hydrocarbons.

Do Titanians worry about too much oxygen in their atmosphere?

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takyon writes:

A study using Cassini's radar observations of Titan's surface has estimated the roughness of its hydrocarbon lakes and seas:

The liquid-hydrocarbon lakes and seas on Titan are incredibly calm, suggesting that future missions to the huge Saturn moon could enjoy a smooth ride to the surface, a new study reports.

The waves rippling the three largest lakes in Titan's northern hemisphere are tiny, according to the study — just 0.25 inches (1 centimeter) high by about 8 inches (20 cm) long.

"There's a lot of interest in one day sending probes to the lakes, and when that's done, you want to have a safe landing, and you don't want a lot of wind," study lead author Cyril Grima, a research associate at the University of Texas Institute for Geophysics (UTIG), said in a statement. "Our study shows that because the waves aren't very high, the winds are likely low."

From older observations:

Calculations of the waves' height suggested they were a puny few centimetres high.

Another way to explore Titan would be to use winged drones or quadcopters, which would be capable of generating more lift than on Earth.

Also at University of Texas at Austin.

Surface roughness of Titan's hydrocarbon seas (DOI: 10.1016/j.epsl.2017.06.007) (DX)

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Phoenix666 writes:

Titan, the largest of Saturn's more than 60 moons, has surprisingly intense rainstorms, according to research by a team of UCLA planetary scientists and geologists. Although the storms are relatively rare—they occur less than once per Titan year, which is 29 and a half Earth years—they occur much more frequently than the scientists expected.

"I would have thought these would be once-a-millennium events, if even that," said Jonathan Mitchell, UCLA associate professor of planetary science and a senior author of the research, which was published Oct. 9 in the journal Nature Geoscience. "So this is quite a surprise."

The storms create massive floods in terrain that are otherwise deserts. Titan's surface is strikingly similar to Earth's, with flowing rivers that spill into great lakes and seas, and the moon has storm clouds that bring seasonal, monsoon-like downpours, Mitchell said. But Titan's precipitation is liquid methane, not water.

"The most intense methane storms in our climate model dump at least a foot of rain a day, which comes close to what we saw in Houston from Hurricane Harvey this summer," said Mitchell, the principal investigator of UCLA's Titan climate modeling research group.

[...] On Earth, intense storms can trigger large flows of sediment that spread into low lands and form cone-shaped features called alluvial fans. In the new study, the UCLA scientists found that regional patterns of extreme rainfall on Titan are correlated with recent detections of alluvial fans, suggesting that they were formed by intense rainstorms.

The finding demonstrates the role of extreme precipitation in shaping Titan's surface, said Seulgi Moon, UCLA assistant professor of geomorphology and a co-senior author of the paper. Moon said the principle likely applies to Mars, which has large alluvial fans of its own, and to other planetary bodies. Greater understanding of the relationship between precipitation and the planetary surfaces could lead to new insights about the impact of climate change on Earth and other planets.

Methane hurricanes. Smoking not advised.

S. P. Faulk et al. Regional patterns of extreme precipitation on Titan consistent with observed alluvial fan distribution, Nature Geoscience (2017). DOI: 10.1038/ngeo3043

Original Submission

takyon writes:

Alien Crystals Unlike Any Found on Earth Might Encrust The Edges of Titan's Lakes

Scientists have recreated Titan-like conditions in a lab, and found that organic molecules from Titan's atmosphere could be forming rings of alien crystals around the methane lakes that dot the Saturn moon's surface.

Previously, the team led by researchers at NASA's Jet Propulsion Laboratory had discovered two of these 'molecular minerals'. Now they've discovered a third, made of acetylene and butane, and believe it could be the most abundant one yet.

"We have demonstrated previously that some organic molecules readily form co-crystals in Titan-relevant conditions, including acetylene," they write in a conference abstract presented this week.

"We report here preliminary evidence for a third co-crystal between acetylene and butane, which could be the most common molecular mineral discovered so far."

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