Titan's ‘Magic Island' Appeared Mysteriously From the Depths
Saturn's moon Titan is known to possess liquid seas and during a recent flyby by NASA's Cassini mission a mysterious formation appeared to rise from the depths. Continue reading →
Saturn's moon Titan is known to possess liquid seas and during a recent flyby by NASA's Cassini mission a mysterious formation appeared to rise from the depths. But then, just as mysteriously as it appeared, "Magic Island" (as it has become known by planetary scientists) vanished.
In a new paper published in the journal Nature Geoscience on Sunday, an international team of researchers have arrived at some explanations for Magic Island. Sadly, none of them point to an extraterrestrial Atlantis.
Titan is the only moon in the solar system to have a thick atmosphere. However, the Saturnian moon is so cold that liquid water cannot exist on its surface. The large bodies of liquids that do exist are composed of methane and ethane - two organic compounds that have very low freezing points and can exist in a liquid state in Titan's frigid environment.
Like Earth's water cycle, Titan's atmosphere is known to have a methane and ethane cycle, where bodies of the liquids accumulate in seas, evaporate, condense and precipitate as a very alien rain. Rivers cut valleys into the landscape and the seas give way to landmasses awash with hydrocarbons. It's for these reasons that scientists are fascinated with this little word and its hazy atmosphere - it is not so dissimilar from a primordial Earth containing the ingredients for life, only in different quantities and much further away from he sun.
So it was with great interest when, on July 10, 2013, Cassini beamed back images of Ligeia Mare, a sea located near Titan's north pole, a bright feature - looking like an island - appeared from the depths. But then, during a follow-up flyby only days later on July 26, the island had gone. Further Cassini flybys confirmed that Magic Island had vanished.
"'Magic island' is a colloquial term that we use within the team to refer to this," Jason Hofgartner, astronomer and lead author from Cornell University, Ithaca, New York, told BBC News. "But we don't actually think it's an island."
So what was it?
Magic Island is "best explained by the occurrence of ephemeral phenomena such as surface waves, rising bubbles, and suspended or floating solids," the researchers write in their publication. In short, they think the feature was caused by an increase in solar energy as the Titan approaches summer in its 30 year seasonal cycle, making the region a more dynamic place.
"Right now, Titan is basically half way between the vernal equinox (August 2009) - at the beginning of spring - and the summer solstice, the start of summer. It's roughly equivalent to what we would consider the beginning of May," said Hofgartner. "As Titan approaches its summer, more of the sun's energy is being deposited in the northern hemisphere."
One explanation centers around the occurrence of huge chunks of methane-ethane ice, similar to Earth's icebergs, that float as the atmosphere warms but sinks as it cools. Another possibility is a mass of organic material that is less dense than the surrounding liquid, allowing it to float or be suspended just below the surface.
Previous observations have shown that Titan's seas can be whipped up sufficiently by surface winds to cause waves and ripples, glinting in sunlight, so this is another possible answer. Volcanic vents releasing gasses through the liquid may also be to blame, creating a disturbance that, from Cassini's perspective, looks like a landmass.
Unfortunately, the mechanisms behind Magic Island will likely remain a mystery until we actually send a mission to investigate Titan's seas.
"These are clearly observations that are close to the limit of detectability - and therefore very difficult to interpret. But it looks like something is going on in Ligeia Mare. Titan surprises us at every turn," John Zarnecki, of the Open University in Milton Keynes who worked on previous studies into Titan's rippled seas, told BBC News.
"Is this feature showing us floating solids or gases erupting at the surface - or a phenomenon that we haven't thought of? After all, we tend to think in terms of Earth-like phenomena. But based on this so far sparse data, any suggestion is likely to be little more than speculation until we get some more supporting information."
Source: BBC News
Ligeia Mare, shown here in a false-color image from NASA's Cassini mission, is the second largest known body of liquid on Saturn's moon Titan. The location where 'Magic Island" appeared is circled in red.
On August 4, the much-anticipated "Wonders of the Solar System" will premier on the Science Channel.
Presenter and physicist Prof. Brian Cox will show you the hidden mysteries of our interplanetary neighborhood, as well as breathtaking sights of the planets, moons and the sun. Cox will also examine some of Earth's extreme environments to see how life has adapted, perhaps helping us understand whether life can exist elsewhere in our solar system. To provide a taster of what you can expect from "Wonders," Discovery News has gathered some facts, figures and the best images of our solar system to assemble a special Wide Angle supporting this groundbreaking documentary. So, let's dive into orbit of the ringed gas giant, Saturn...
Moons of Saturn: Enceladus
Welcome to Enceladus, one of Saturn's icy inner moons. The streams of light you see are actually jets of water shooting out of the surface. The Cassini spacecraft discovered the geysers in December 2005, shown here in false-color. Researchers think gravitational kneading of its core heats subsurface water into vapor, causing it to spew out of the moon's chilly -328 degrees F surface.
Moons of Saturn: Tethys
This 665-mile-wide moon of Saturn, pronounced "teeth-this," has an ice-covered surface criss-crossed with cracks and faults. In this Cassini snapshot, a small mountain range inside the Odysseus crater can be seen. Covering about two-fifths of Tethys' surface, the crater is enormous, and the mountains are thought to have formed from shifting surface ice.
Moons of Saturn: Epimetheus
Set against a large smoky Titan and Saturn rings, Epimetheus stands out as the "lil' white moon," as scientists have nicknamed it. This image is in false color, but not without purpose. It allows us to see Titan, Saturn and Epimetheus clearly and compare their sizes -- Epimetheus is 72 miles across while giant Titan is 3,200 miles across.
Moons of Saturn: Pan
Like its storybook counterpart, Saturn's moon Pan likes to play around. Cassini found it on Aug. 1, 2005 circling in and out the Encke Gap of Saturn's A ring, shown here. Pan is small compared to some of its brothers and sisters -- only 16 miles across -- and looks something like a walnut. Despite its small size, Cassini was able to capture it from about 500,000 miles away.
Moons of Saturn: Iapetus
What is Saturn's walnut-shaped moon Iapetus covered in? Scientists think perhaps a bit of both dust and ice, though the particulars are sketchy. The moon's mysterious dark splotches are probably made of carbon-based gunk that seeped from below. By using Cassini's images, NASA researchers determined that the carbon residues came from sub-surface volcanoes or geysers similar to those found on Enceladus.
Moons of Saturn: Phoebe
This hunk of rock circling Saturn under the guise of a moon could have once been a comet. Cassini snapped this photo on June 30, 2004 and researchers have since been studying its unusual pox surface, backwards orbit, low density and extremely dark features. They think Phoebe might have been a Kuiper Belt object close to Neptune before Saturn's gravitational pull snagged it.
Moons of Saturn: Mimas
Nope, this isn't the Death Star hanging around Saturn for its chance to blast Earth. This is Mimas, and it's a lucky survivor from an ancient, colossal collision. At 80 miles wide, the "eye" -- called Herschel crater -- covers a good portion of the 247-mile-wide moon.
Moons of Saturn: Hyperion
This strange Saturn moon might look like a rocky sponge, but scientists think Hyperion is made mostly of ice. Cassini shot this high-contrast image in 2005 to peek down inside the thousands of craters bored into its surface. What did it find? Mysterious dark gunk that might be a few feet thick in places.
Moons of Saturn: Dione
Giovanni Cassini, who spent a good part of his life looking at Saturn through a telescope, discovered Dione in 1684. Like most Saturn satellites, it's made mostly of ice. The Cassini spacecraft -- named after you-know-who -- found cliffs of ice hundreds of feet high in late 2004. Scientists think movement of the crust split it open to create the towering structures.
Moons of Saturn: Titan
Scientists think of Titan, mightiest of all the Saturn moons, as a sort of early Earth chock full of organic compounds and a thick atmosphere. In January 2005, the Huygens probe landed on Titan's surface, revealing many of the orange-brown world's secrets. That makes Titan the only moon aside from Earth's to receive a robotic surface visit from humans. This false-color photo shows Titan's surface in green and its sunlight-absorbing stratosphere in red.
Moons of Saturn: Janus
Janus is a tiny, potato-shaped satellite that is typical of Saturn's 17-plus moons: cratered and icy. It's the big brother to the moon Epimetheus, which hangs out in nearly the same orbit. By studying Cassini spacecraft images closely, scientists have noticed both moons hang out in a thin but wide ring of dust and ice -- likely the leftovers of meteorite impacts over the eons.
Moons of Saturn: Rhea
Sadly, Saturn's 949-mile-wide moon Rhea doesn't look like this in normal light. The image is cast in false color (for scientific reasons, of course) using images taken in several different wavelengths. Scientists aren't certain what to make of the stripes that appear in the composite image, but they do think Rhea is about one part rock and three parts ice. Like Dione, it also seems to have huge cliffs of ice.
Slide show originally published in June 2008.