Somewhatsurprising findingshave suggested that Titan ’s climate has importantly shifted at some point in the past . Whereas today this moon of Saturn only has bodies of liquid at its perch , grounds points to equatorial regions once being abundant in lakes and seas .
Titan is already known to have eubstance of liquid on its airfoil , but unlike Earth these are compile of liquid hydrocarbon , methane and ethane , rather than urine . Nonetheless , the front of these liquids fix Titan one of the most dry land - like places in the Solar System .
simulacrum from theRADAR instrumenton the Cassini spacecraft have shown that Titan has dunes on itssurface , with up to 17 percent of its surface believed to be covered in these features . But late depth psychology has identified a new feature : mega - yardangs . These are wind - eroded rocky structures and ridges that are mould in soft deposits in empty lake basins . We have numerous example on Earth . And now scientists have seen some on Titan , too .
Crucially , they were find in Titan ’s equatorial regions – suggesting these realm were once notably wetter than their New dry show .
" Finding yardangs at mid - latitude on Titan mean that lakes might have existed there at some peak in the Sun Myung Moon ’s past , " Nicolas Altobelli , ESA ’s Cassini - Huygens projection scientist , said in astatement . " As they ’re certainly not there now , it ’s a secure polarity for natural clime modification . This just add to the moon ’s intrigue – there ’s much more for us to explore . "
Sand dunes and mega - yardangs on Earth . ESA / DLR
Sand dunes and mega - yardangs on Titan . NASA / JPL - Caltech / ASI / ESA
Quite what occur during this change in climate is n’t clear . As the average surface temperature of Titan is currently around -180 ° C ( -290 ° F ) , though , it would have had to be significantly warmer in the equatorial region for liquid to live there .
The researchers , who issue their results inIcarus , come to their conclusion by compare range of Titan from space , specifically the Cassini mission , with similar images of Earth film by theTerraSAR - X satellite . get laid as comparative planetology , the squad was able to key mega - yardangs both on Earth and on Titan , despite the image of Titan being of a significantly lower resolution .
" Comparing feature on different planets is a very powerful approach , " articulate Philippe Paillou of the Université de Bordeaux , France , lead author of the study , in the command . " It helps us to sympathise the geology of regions we ca n’t directly get at . Fieldwork on Titan is still a dream , but by using Earth ’s surface as an analog we can acquire immense amounts about Titan ’s surface , despite it being over a billion kilometres away . "
