A new study by University of Arkansas researchers could help explain the appearance of so-called “magic islands” in the icy hydrocarbon lakes of Titan, Saturn’s largest moon.
Kendra Farnsworth, a doctoral candidate in the Arkansas Center for Space and Planetary Sciences and first author of the study, published in the journal Geophysical Research Letters, re-created Titan’s atmospheric conditions in one of the center’s five planetary simulation chambers. Farnsworth found that under Titan-like conditions, a combination of methane, ethane and nitrogen produced rapid bubble formation. The bubbles are a possible explanation for the transient islands that show up on some radar mapping scans of Titan by NASA’s Cassini probe, but not on others.
Titan is the only place in the solar system besides Earth known to have liquid rivers, lakes and seas. It is far too cold (about minus 290 degrees Fahrenheit) for liquid water, though scientists believe the moon may have a water ocean below its crust. Instead, the surface liquids are a mixture of methane and ethane, both of which are gases on Earth.
Bubbles forming in the moon’s lakes and rivers could be vigorous enough to shape the planet’s geology, the researchers wrote. “Bubbles may be common in Titan’s lakes and may be significant in the geologic processing of Titan’s river outlets, such as the development of deltas in Ontario Lacus.”