Scientists looking at the lake region of Titan's north pole see signs of dried lake beds like the Bonneville Salt Flats near Utah's Great Salt Lake.
Saturn's moon Titan hosts the equivalents of Utah's Bonneville Salt Flats – dried lake beds strewn with compounds left behind by evaporation – over a much wider expanse of the moon's north polar region than previous observations indicated, according to scientists.
New images delivered by NASA's Cassini orbiter also hint that much of Titan's northern region shares a common underlying geology, an observation that could help unravel the mystery of how the lakes formed and why most of the moon's lakes and all of its seas appear near the north pole.
The images mark the first time Cassini has been able to capture the entire north pole, according to Elizabeth Turtle, a planetary scientist at The Johns Hopkins University's Applied Physics Laboratory in Laurel, Md., and a member of the Cassini science team.
The new images, which NASA released Wednesday, “have the potential to change our understanding of the north pole” of Titan, Dr. Turtle says.
Many planetary scientists view Titan as a time capsule, giving them a glimpse of what conditions on Earth might have been like before life emerged. Though Earth is much warmer than Titan, the moon hosts an inventory of organic compounds thought to be similar to those on Earth before life took hold. And the processes shaping Titan's surface – from flowing liquids to volcanic action – mirror those of Earth. Indeed, some astrobiologists posit that simple forms of life may exist below Titan's surface.
Unlike Earth, however, where lakes and ocean basins are filled with water, Titan's lakes are filled with methane and ethane. They fill lakes and seas, fall as rain, and etch channels as they flow along Titan's icy surface. (On the much-warmer Earth, these hydrocarbons appear as gases.)
Since its arrival in the Saturn system in 2004, Cassini has performed 94 close flybys of Titan. Researchers have identified and named three seas and 34 lakes, seven of which are dry lakes.
Two years ago, a team led by University of Idaho planetary scientist Jason Barnes identified what they interpreted as residue from evaporation on the beds of some of Titan's northern dry lakes. On Earth, such residue shows up as deposits of calcium carbonate, calcium sulfate, or salts. On Titan the residue would show up as solid organic compounds,