'Magic Island' pops up on Saturn's moon, Titan, giving astronomers a mystery to solve
Monday, June 23, 2014, 3:18 -
Saturn's largest moon, Titan, is a true wonder of our solar system, and it continues to surprise even after nearly a decade of exploration by NASA's Cassini spacecraft. The latest discovery, made by astronomers at Cornell University, is the appearance of a mysterious formation in one of the moon's hydrocarbon lakes.
Ever since the Cassini spacecraft arrived at Saturn, just shy of 10 years ago, it has been making periodic flybys of Titan - Saturn's largest moon, which is known for its dense nitrogen and methane atmosphere and abundant hydrocarbon seas and lakes. On these passes, Titan takes radar images of the surface of the moon, so that it can see through the dense clouds that shroud the surface from its cameras, and return that information to researchers here on Earth. On July 10, 2013, while flying over Titan's second largest sea, known as Ligeia Mare, the radar picked up something strange - a bright splotch along the sea-coast that had never been seen before and which disappeared shortly thereafter. Although the researchers referred to as a 'transient feature' in their paper, published in the journal Nature on June 22, according to the Cornell Chronicle, they informally named it 'The Magic Island.'
"This discovery tells us that the liquids in Titan's northern hemisphere are not simply stagnant and unchanging, but rather that changes do occur," said study lead author Jason Hofgartner, who is earning his PhD in planetary sciences at Cornell, according to the news release. "We don’t know precisely what caused this ‘magic island’ to appear, but we'd like to study it further."
Even before studying it further, though, Hofgartner and the other researchers do have a few ideas about what it may be. Wave crests, driven by winds, could have been picked up by the radar. Solids suspended in the liquid methane and ethane of the sea have have shown up on radar or solids that sank to the bottom in winter may have became buoyant now that Titan's northern hemisphere is in late spring. It could also be bubbles of gas rising from the sea floor.
"Likely, several different processes - such as wind, rain and tides - might affect the methane and ethane lakes on Titan," Hofgartner said in the statement. "We want to see the similarities and differences from geological processes that occur here on Earth."
"Ultimately," he added, "it will help us to understand better our own liquid environments here on the Earth."
Launched in October of 1997, NASA's Cassini spacecraft will be celebrating the 10th anniversary of its arrival in Saturn orbit on July 1, 2014. The probe has returned some amazing finds about Saturn and its moons, including some truly breathtaking images (even one of Earth!). The spacecraft's time is growing short, though. Towards the end of 2016, it will begin the final phase of its mission, making 22 orbital loops that will have it flying close enough to Saturn's atmosphere that it will pass through the gap between the planet and its innermost ring. This is the closest that any of our spacecraft have ever come to the planet, and astronomers here on Earth are preparing themselves for some spectacular views.