Scientists have been captivated by a feature (dubbed “Magic Island”) in Ligeia Mare, one of the largest seas on Titan. In 2007, NASA’s Cassini spacecraft captured a radar image of this sea. Everything looked normal. That changed in subsequent flybys in 2013, 2014 and 2015.
Here’s another image from a different angle.
You can see what scientists describe as a “transient feature” appear in the 2013 photo. It’s still visible in the 2014 photo before disappearing in 2015.
What are we looking at? Scientists double checked to make sure this wasn’t an image artifact. Features like this are exciting, but you don’t want to announce something only to retract it because of artifacts. The image was good. Next, they looked into evaporation. But the shoreline of Ligeia Mare hasn’t changed noticeably.
Recent research points to a much more intriguing force. Surface waves. Scientists believe Titan’s liquid hydrocarbon seas are home to wave action.
“It’s really exciting, as we’ve confirmed that Titan’s seas are active environments,” says Jason Hofgartner, a NASA postdoctoral researcher at JPL the paper’s lead author. “There are stable liquids on the surface of Titan, and processes acting on these liquids are similar to those on Earth. Titan’s seas – though composed of liquid methane and ethane – are not stagnant but rather dynamic environments.”
Other possibilities are floating solids or bubbles, but scientists believe waves are the most likely culprit.
Did you know: Ligeia Mare is the second largest liquid body on Titan and is larger than the largest Great Lake – Lake Superior. The biggest body of liquid on Titan is Kraken Mare, named after the legendary sea monster.
Cassini may solve the mystery once and for all. 2016 and 2017 will be full of Titan flybys. It’s the final Titan flyby in 2017 that scientists will be looking carefully at Ligeia Mare. On April 22, 2017, Cassini will fly by Titan at an altitude of just 608 miles.
The year of Titan
Several flybys of Saturn’s largest planet have already happened. And many more are planned. The next flyby will be on April 4 with Cassini zooming past at just 615 miles away. This close encounter will focus on atmospheric measurements.
Additional flybys are expected on May 6 (603 miles away), June 7 (606 miles away), July 25 (607 miles away), August 10 (994 miles away) and many more.
On November 14, Cassini will gather more data about Titan’s three major northern seas and determine if there any significant differences between them. You can read about every flyby in 2016 here.
Planning your next beach vacation to Ligeia Mare? You better bring a badass wetsuit. Temperatures are a chilly 290 degrees below zero.
Image credits: NASA/Cassini