Last year the lakes at the north pole of Titan were partly filled, seemingly evaporated. It's likely the evaporation contributed to this cloud formation.

The clouds are made up of ethane, methane and other organics. These findings reinforce the idea that methane rains down onto the surface forming lakes, then evaporates to form clouds. Scientists compare this methane cycle to our hydrological cycle on Earth, dubbing it "methane-ologic cycle."

The cloud, which is roughly half the size of the United States, is expected to be around for several years.

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