The Cassini probe had spotted strange brilliances that appeared and disappeared over the polar regions of Titan, Saturn’s satellite. The mystery has just been solved: bubbles of dinitrogen emerge on the surface of the seas.
The radar of the Cassini probe had spotted them several times: shiny points appearing and disappearing at the mercy of the ocean’s overflights of the polar regions of Saturn’s biggest moon, Titan. The phenomenon that had been dubbed „Magic Islands“ has just found an explanation: it is the bubbles of nitrogen gas (N 2 ) that rise to the surface periodically. At the origin of the understanding of this enigma, works published in the journal Nature Geosciences , led by an international team under the direction of Daniel Cordier of the group of molecular and atmospheric spectrometry (GSMA) of Reims.
Atmospheric Instability
Even before the arrival of the Nasa Cassini probe and its Huygens module manufactured by the ESA European Space Agency, Titan was fantasizing the astrophysicists: It was often baptized as the little sister of the Earth. Indeed, it is the only star of the solar system to have a dense atmosphere – that is to say 1.5 times the atmospheric pressure even if the temperature is in the vicinity of -180 ° C. The latter is almost entirely composed of diazote N 2 with traces of methane (CH 4 ) and of ethane (C 2 H 6 ). The surface of Titan presents several lakes and seas of hydrocarbons coming from a complex chemistry and it is on the surface of one of them that the “ Strange phenomenon has been spotted: Ligeia Mare is precisely one of the largest seas in the polar regions. However, Cassini’s radar spotted a particular shine on July 10, 2013, which appeared to be absent during the July 26, 2013 flyby.
Different hypotheses have been approached to explain this oddity: a floating object on the surface of the seas? A wave?
None of this, indicate the recent work: the pressure at the bottom of Ligeia Mare makes the mixture dazole, ethane and methane unstable … which produces dinitrogen bubbles on the surface of this sea, detected as shiny points By radars.
