By Science Alert Staff
The object is scientifically known as a “transient feature” but astronomers have playfully dubbed it the “magic island”.
This could be the first time dynamic geological processes have been observed in Titan’s northern hemisphere. The research is published in Nature Geoscience.
“This discovery tells us that the liquids in Titan’s northern hemisphere are not simply stagnant and unchanging, but rather that changes do occur,” Jason Hofgartner from Cornell University in the US and the lead author said in a press release.
The researchers are now studying the “magic island” further.
Titan is the largest of Saturn’s 62 known moons and is covered in lakes and seas. Beneath its thick atmosphere, which is lethal to humans, it closely resembles a smaller, watery Earth – with wind and rain creating familiar landscapes such as mountains, dunes and lakes. It’s the only place other than Earth known to have stable liquids on its surface and falling rain.
But instead of water, icy cold liquid methane and ethane flows through its river-like channels and into its seas, and its dunes are made of hydrocarbon.
The second largest of these seas is the 150-metre-deep Ligeia Mare, where astronomers noticed the unusual geological feature in an image taken by the Cassini spacecraft on 10 July 2013. The island appeared around 9.6 km off the sea’s southern shore. Pictures taken of the same spot previously and a few days later showed no geological features there.
Titan’s northern hemisphere is currently transitioning from spring to summer, seasons which last much longer on the moon than on Earth, and the scientists believe this change could have triggered this mysterious island to appear temporarily.