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Bubble streams in Titan’s seas as a product of liquid N2 + CH4 + C2H6 cryogenic mixture


Titan, Saturn’s largest moon, is the only extraterrestrial body known to support stable liquid on its surface, in the form of seas and lakes that dot the polar regions. Many indications suggest that the liquid should be composed of a mixture of nitrogen, methane and ethane. Recent observations by Cassini’s Radio Detection and Ranging (RADAR) instrument of Titan’s large sea, called Ligeia Mare, have shown unexplained and ephemeral bright features, possibly due to rising bubbles. Here we report that our numerical model, when combined with experimental data found in the literature, shows that Ligeia Mare’s bed is a favourable place for nitrogen exsolution. This process could produce centimetre-sized and RADAR-detectable bubbles.

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Figure 1: The behaviour of a ternary mixture, N2 + CH4 + C2 H6, at three temperature values relevant to the subsurface environment of Titan’s sea.


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Author information




D.C. wrote the paper and performed PC-SAFT computations, F.G.-S. and D.N.J.-G. made the stability analysis of the N2 + CH4 + C2H6 mixtures, and G.L.-B. provided expertise on the physics of bubbles and effervescence.

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Correspondence to Daniel Cordier.

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The authors declare no competing financial interests.

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Supplementary Tables 1–3 (PDF 84 kb)

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Cordier, D., García-Sánchez, F., Justo-García, D. et al. Bubble streams in Titan’s seas as a product of liquid N2 + CH4 + C2H6 cryogenic mixture. Nat Astron 1, 0102 (2017).

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