NASA's Cassini reveals new surprises with Titan's lakesChristian Fernsby ▼ |
World They provide new information about the way liquid methane rains
On its final flyby of Saturn's largest moon in 2017, NASA's Cassini spacecraft gathered radar data revealing that the small liquid lakes in Titan's northern hemisphere are surprisingly deep, perched atop hills and filled with methane.
They provide new information about the way liquid methane rains, evaporates from and seeps into Titan the only planetary body in our solar system other than Earth known to have stable liquid on its surface.
Scientists have known that Titan's hydrologic cycle works similarly to Earth's with one major difference.
Instead of water evaporating from seas, forming clouds and rain, Titan does it all with methane and ethane.
We tend to think of these hydrocarbons as a gas on Earth, unless they're pressurized in a tank.
But Titan is so cold that they behave as liquids, like gasoline at room temperature on our planet.
Scientists have known that the much larger northern seas are filled with methane, but finding the smaller northern lakes filled mostly with methane was a surprise.
Previously, Cassini data measured Ontario Lacus, the only major lake in Titan's southern hemisphere.
There they found a roughly equal mix of methane and ethane.
Ethane is slightly heavier than methane, with more carbon and hydrogen atoms in its makeup. ■
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