After years of searching, planetary scientists think they may finally have spotted waves rippling on the seas of Titan, Saturnís largest moon. If confirmed, this would be the first discovery of ocean waves beyond Earth. NASAís Cassini spacecraft spied several unusual glints of sunlight off the surface of Punga Mare, one of Titanís hydrocarbon seas, in 2012 and 2013. Those reflections may come from tiny ripples, no more than 2 centimetres high, that are disturbing the otherwise flat ocean, says Jason Barnes, a planetary scientist at the University of Idaho in Moscow. Researchers expect more waves to appear in the next few years, because winds are anticipated to pick up as Titanís northern hemisphere ó where most of its seas are located ó emerges from winter and approaches spring.
Barnes presented the findings recently at the Lunar and Planetary Science Conference, where a second talk hinted at the presence of waves in another of Titanís seas. A second report at the conference also hints at possible waves. Last summer, Cassini scientists spotted what they called a Ďmagic islandí in another sea, Ligeia Mare, that appeared and then disappeared. It looked like a bright reflection in one image but was not visible 16 days later or in any photographs taken since, said Jason Hofgartner, a planetary scientist at Cornell University in Ithaca, New York. After ruling out possibilities such as an island exposed by a change in sea level, the team concluded that the Ďmagic islandí is probably a set of waves, a group of bubbles rising from below the surface or a suspended mass, such as an iceberg.The Ligeia Mare researchers may have better luck than Barnes and his colleagues ó a Cassini fly-by in August should be able to image this particular area of Ligeia Mare and hunt for waves again.
Reposted by permission from Macmillan Publishers Ltd; License no: 3352431137077; Nature News; First hints of waves on Titan's seas, Alexandra Witze, Mar 17, 2014