Mapping Titan has kept Cassini pretty busy and it is not like she hasn’t seen lakes before; lakes of methane and ethane, but that was in Titan’s northern regions. What is different? These lakes are giving readings that have led scientists to believe that there is a hydrologic cycle at work. Hydrocarbons rain down to the surface, collect in the lakes, then, evaporate back to the atmosphere. And when the lakes evaporate? A deposit of yet unidentified material is deposited.
Earlier fly-bys of the same region resulted in distant viewing of possible lakes and terrain, but thanks to Titan’s weather cycle, rain-free weather and other seasonal changes, the VIMS instrument was able to obtain a much better view.
Scientists were previously missing the final step in the cycle of Titan’s hydrocarbons; the piece that places the liquid hydrocarbons back into the atmosphere.
In a NASA news release Jason Barnes, a participating scientist for the VIMS instrument at the University of Idaho said that “It turns out that Titan's north pole is even more interesting than we thought, with a complex interplay of liquids in lakes and seas and deposits left from the evaporation of past lakes and seas."
So- what of the unidentified material? Scientists aren’t sure. It seems to be the equivalent of Earth’s Salt Flats, but in a different atmosphere. The cycle that has allowed the evaporation and return to the atmosphere of the liquid hydrocarbons leaves the organic compound.
This chemistry set that is Titan apparently is the exact environment necessary for the kind of prebiotic chemistry that preceded our existence on Earth.
Perhaps our next rover will be sent to explore on the grounds of Titan – seems it might be worth our while!