Research press release


Nature Geoscience

Possible waves spotted in a Titan sea


Jason Hofgartnerたちは、タイタンの北極海であるライジーア・メア(Ligeia Mare)で明るい特徴があることをカッシーニのレーダー・データから見つけた。明るい場所は、その前後のレーダー画像には見られないので、一時的な特徴であると示唆される。観測された特徴は、液体メタンの海の中あるいは上を伝わる表面波、上昇する泡、あるいは浮遊する物体と一致する。


The northern seas on Saturn’s largest moon Titan could be experiencing seasonal phenomena similar to those found in Earth’s lakes, such as waves and bubbles, according to a study published online in Nature Geoscience. NASA’s Cassini spacecraft has been monitoring Titan since 2004, but this is its first glimpse of active surface processes in the moon’s northern hemisphere as the season slowly shifts towards summer.

Jason Hofgartner and colleagues identified bright features in Titan’s northern polar sea, Ligeia Mare, in the Cassini radar data. The bright spots were not seen in earlier or later radar images, suggesting that they are transient features. The observed features are consistent with surface waves, rising bubbles, or floating objects in or on the liquid methane sea.

Titan, with a methane cycle analogous to the Earth’s water cycle, is the only other planetary body in the Solar System with pools of stable liquid on its surface. The findings suggest that the active surface processes occurring in Titan’s seas may be an expression of the changing seasons, similarly to processes in Earth’s lakes.

doi: 10.1038/ngeo2190


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