Scientists Discover Evidence of Summer Rain and Changing Seasons On Titan

Thursday, 17 January 2019 - 11:43AM
Solar System
Thursday, 17 January 2019 - 11:43AM
Scientists Discover Evidence of Summer Rain and Changing Seasons On Titan
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Image credit: NASA/ESA/IPGP/Labex UnivEarthS/University Paris Diderot
Saturn's moon Titan has been heralded as a possible home for extraterrestrial life and a target for future human colonies, largely due to Cassini's discovery of Earth-like oceans, lakes, and the presence of water ice its liquid methane-rich surface. Now there's even more data that makes the icy giant resemble our planetary home. Researchers at the University of Idaho analyzed an image taken by Cassini in 2016 and found evidence of rain and changing seasons on Titan's north pole. 

The researchers, led by doctoral student Rhajani Dhingra, attributed the finding to a careful analysis of a photograph captured by Cassini's near‐infrared instrument, the Visual and Infrared Mapping Spectrometer (VIMS), on June 7, 2016. The photograph showed a large reflective area covering 46,332 square miles that did not appear in Cassini's previous or subsequent fly-bys. Describing their methodology in an article published in Geophysical Research Letters on Wednesday, the researchers write that "based on the overall brightness, spectral characteristics, and geologic context, we attribute this new feature to specular reflections from a rain‐wetted solid surface like those off of a sunlit wet sidewalk. The reported observation is the first documented rainfall event at Titan's north pole and heralds the arrival of the northern summer (through climatic evidence), which has been delayed relative to model predictions."

In other words, the reflection was likely that of light glinting off a vast quantity of liquid that had not been previously observed.

"It's like looking at a sunlit wet sidewalk," Dhingra said in a press release.

Credit: NASA/JPL/University of Arizona/University of Idaho.
Credit: NASA/JPL/University of Arizona/University of Idaho.

Although nothing is certain, the "sidewalk effect" theory is leading the team to continue to look for additional evidence of rain.
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