Ontario Lacus

lake, Titan

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July 19, 2026

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Ontario Lacus is a lake on Saturn's moon Titan, notable for being one of the few known bodies in the solar system with liquid on its surface. It is located in the south polar region of Titan and has a shrinking shoreline. Titan itself is Saturn's largest moon and the only one with clouds and a dense atmosphere, resembling a planet more than a typical moon. Its atmosphere is primarily nitrogen with methane, and its surface features lakes and dunes, sculpted by wind and methane rain. In contrast, Lake Ontario is one of the Great Lakes of North America, situated between Canada and the United States.1234

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Titan
The surface of Titan
A smaller lake, Ontario Lacus, with a shrinking shoreline, has been observed in the south polar region. Reflections of the Sun have been observed on the lakes that confirm that they are filled with liquids rather than ice or sand.
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A smaller lake, Ontario Lacus, with a shrinking shoreline, has been observed in the south polar region. Reflections of the Sun have been observed on the lakes that confirm that they are filled with liquids rather than ice or sand.
Read More