Volcano-like features have been found in the polar regions of Saturn's moon Titan by NASA's Cassini spacecraft. "The close association of the proposed volcanic craters with polar lakes is consistent with a volcanic origin through explosive eruptions followed by collapse, as either maars or calderas," scientist Charles A. Wood said.
"The apparent freshness of some craters may mean that volcanism has been relatively recently active on Titan or even continues today," added Mr Wood.
Features such as nested collapses, elevated ramparts, halos, and islands indicate that some of the small depressions in the north polar region of Titan are volcanic collapse craters, according to a paper "Morphologic Evidence for Volcanic Craters near Titan''s North Polar Region" that appears in the Journal of Geophysical Research: Planets. A few similar depressions also occur near the south pole of Titan.
Many landforms on Saturn's moon Titan are like those found on Earth. This has been revealed by the Cassini mission. There are sand dunes, river valleys and lakes. These features are due to temperature differences on the planet's surface because of the Sun's heat.
"We demonstrated that there is also evidence for internal heat, manifest at the surface as cryovolcanoes, made from melting the ice crust into liquid water that erupts onto Titan's surface," Mr Wood said.
"These features are roughly round, with raised rims, and they sometimes overlap each other. They are consistent with the shapes of other volcanic landforms on Earth and Mars formed by the explosion, excavation and collapse," the scientist added.