Mysterious Feature Appears and Disappears In a Sea On Titan

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Mysterious Feature Appears and Disappears In a Sea On Titan

Posted by Soulskill on Tuesday September 30, 2014 @03:03PM from the interplanetary-game-of-battleship dept.

schwit1 writes: Cassini images taken in 2007, 2013, and 2014 of one of Titan's largest hydrocarbon seas find that a mysterious feature there keeps appearing and disappearing. Quoting: "The mysterious feature, which appears bright in radar images against the dark background of the liquid sea, was first spotted during Cassini's July 2013 Titan flyby. Previous observations showed no sign of bright features in that part of Ligeia Mare. Scientists were perplexed to find the feature had vanished when they looked again, over several months, with low-resolution radar and Cassini's infrared imager. This led some team members to suggest it might have been a transient feature. But during Cassini's flyby on August 21, 2014, the feature was again visible, and its appearance had changed during the 11 months since it was last seen.

Scientists on the radar team are confident that the feature is not an artifact, or flaw, in their data, which would have been one of the simplest explanations. They also do not see evidence that its appearance results from evaporation in the sea, as the overall shoreline of Ligeia Mare has not changed noticeably. The team has suggested the feature could be surface waves, rising bubbles, floating solids, solids suspended just below the surface, or perhaps something more exotic." That the seasons are slowly changing on Titan is probably contributing to the transient nature of this feature.

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Nessie? by WillKemp · 2014-09-30 15:25 · Score: 1

The Loch Ness monster hasn't been seen for a while.
Simple(x)st explanation by antifoidulus · 2014-09-30 15:29 · Score: 1

It's planetary herpes

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The tide went out by Technician · 2014-09-30 15:32 · Score: 2

Sandbar and tides maybe?

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1. Re:The tide went out by BarbaraHudson · 2014-09-30 15:36 · Score: 5, Funny
  
  Features randomly appearing, disappearing, and reappearing? Who knew that these scientists were running slashdot BETA on the Cassini probe?
  
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2. Re:The tide went out by citizenr · 2014-09-30 16:10 · Score: 2
  
  lets hope for derelict spaceship
  but its probably just ice floating in liquid methane :(
  
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3. Re:The tide went out by Tablizer · 2014-09-30 16:56 · Score: 5, Funny
  
  Dice is gonna start Titaning the reins on you.
  
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4. Re:The tide went out by mister_playboy · 2014-10-01 02:32 · Score: 1
  
  No need to Pan his finely tuned sense of humor!
  
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subsurface terrain & tides by ihtoit · 2014-09-30 15:40 · Score: 3, Informative

we have it on Earth: sea terrain that's only visible at low tide - think sandbars to mountain ranges. The Mid Atlantic Ridge is the prime example of the latter (some islands submerge during high tide), the only example I can think of of a semi-permanent sandbar feature is Dogger Bank in the North Sea which during storm surges has been known to exposure to the air from several dozen feet down. Don't forget also that Titan orbits a primary that's quite a bit more massive than Earth and is itself twice as massive as Luna. Tidal effects will necessarily be more pronounced.

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1. Re:subsurface terrain & tides by Anonymous Coward · 2014-09-30 16:52 · Score: 5, Informative
  
  Except for the mention that the rest of the shore line doesn't change...
2. Re:subsurface terrain & tides by Tablizer · 2014-09-30 17:04 · Score: 1
  
  Simple, tides caused by a small local moon.
  
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3. Re:subsurface terrain & tides by Man+On+Pink+Corner · 2014-09-30 17:40 · Score: 2
  
  In eel-infested waters.
4. Re:subsurface terrain & tides by ArcadeMan · 2014-09-30 18:13 · Score: 2
  
  That's no moon...
  
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5. Re:subsurface terrain & tides by oobayly · 2014-09-30 20:22 · Score: 1
  
  The Bramble Bank in the central Solent does the same. It's also the location for an annual cricket match. I've hit it numerous time when racing, but never actually seen it.
6. Re:subsurface terrain & tides by jeffb+(2.718) · 2014-10-01 02:06 · Score: 1
  
  Bottomos?
7. Re:subsurface terrain & tides by Agent0013 · 2014-10-01 02:07 · Score: 1
  
  If the shore line is made up of vertical cliffs then it wouldn't change at all even if the level of the sea changed by a lot.
  
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8. Re:subsurface terrain & tides by Captain+Hook · 2014-10-01 02:56 · Score: 1
  
  I know it's unlikely, but if the shore was made up largely of vertical walls rather than slopes, then a tide wouldn't change the shore line much but could reveal sub surface shelves.
  
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9. Re:subsurface terrain & tides by mister_playboy · 2014-10-01 03:10 · Score: 1
  
  Moons of planetary moons would be subject to tidal forces that would cause their orbits to decay over time periods that are short by astronomical standards.
  
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10. Re:subsurface terrain & tides by Archangel+Michael · 2014-10-01 03:25 · Score: 1
  
  That's not a moon!
  
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11. Re:subsurface terrain & tides by ihtoit · 2014-10-01 10:55 · Score: 1
  
  The eccentricity of the orbit does not need to be high, but because a tidally locked body tends to circularize its orbit, you need another moon or body that sustains the orbital eccentricity. Saturn has several dozen moons.
  So what happens then is that as the body comes closer to the primary, it gets stretched more due to gravitational gradient and when it orbits further away, it reshapes itself to more closely resemble a sphere.
  Io's crust raises and drops about 100 meters as it orbits around Jupiter. Its eccentricity is sustained by a 1:2:4 resonance with Europa and Callisto and is tidally locked with Jupiter.
  If you think of tides as rising and falling surface, then yes, a tidally locked body can have tides.
  As Titan is also in an eccentric orbit, the tidal influence pulls the moon into weird contortions - those tides are between 60 and 96 times stronger than Luna's influence on Earth. There will also be a bulge which moves, considering the orbital speed which changes constantly and the rotation which is constant, the net visual effect from Titan's surface is that Saturn librates. From the surface of Saturn (stick with me), we see way more of Titan's surface than we would if it were in a perfectly circular orbit. ALSO: consider Titan's atmosphere, which is half again the density of Earth's. All that fluid will be even more affected by tides, as will any liquid bodies such as seas of methane - no matter how fairly static those tidal influences, they are still moving, and moving against a superrotating atmosphere.
  
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aliens by Anonymous Coward · 2014-09-30 15:45 · Score: 1

aliens
ok by the_Bionic_lemming · 2014-09-30 15:48 · Score: 1

Why didn't they outline the islands directly north of the "blip" that are smears on the first pic and outlined on the sharper picture years later?

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1. Re:ok by the_Bionic_lemming · 2014-09-30 15:55 · Score: 1
  
  In fact, I think they tweaked the code to read the images over the past seven years.
  
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Re: it's R'lyeh by Jeremiah+Cornelius · 2014-09-30 15:59 · Score: 3, Funny

It's the effluvia released, every time Titan ejects another black, slab-like monolith.

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It's a methano-whale! by macraig · 2014-09-30 16:33 · Score: 1

Calling Captain Ahab....
1. Re:It's a methano-whale! by Jason+Levine · 2014-10-01 00:33 · Score: 1
  
  A methano-whale?
  "We're whalers on the moon (of Saturn)! We carry a harpoon! ..."
  
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Walrus and Carpenter. by Anonymous Coward · 2014-09-30 16:44 · Score: 1

And while the sea is Boiling hot...
for methane that is.
Methanogen algae blooms? by Anonymous Coward · 2014-09-30 17:31 · Score: 2, Insightful

I can hope, right?!
1. Re:Methanogen algae blooms? by dgatwood · 2014-10-01 06:18 · Score: 1
  
  I was kind of hoping for some sort of creature deciding to try to crawl out onto dry land, finding no actual land, saying "screw it", and crawling back under the ice.
  
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Kraken Mare by Pikoro · 2014-09-30 17:56 · Score: 3, Interesting

The sea is called Kraken Mare. I think we all know what that means this is...

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Stop clicking OK! by sjames · 2014-09-30 19:05 · Score: 1, Funny

They must be clicking OK when Sony offers to update Titan's firmware. That is the leading cause of disappearing features. Of course it could be LG...
Run For Your Lives... by StreetChip · 2014-09-30 19:49 · Score: 1

It's Godzilla!

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Tides... by DeBattell · 2014-09-30 22:51 · Score: 1

Tides come in, tides go out you can't explain that.
1. Re:Tides... by Jason+Levine · 2014-10-01 00:34 · Score: 1
  
  The rest of the shoreline isn't changing, though. If it was tide-related, you'd expect the entire shoreline to change, not just one section in the middle of the sea.
  
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2. Re:Tides... by Agent0013 · 2014-10-01 02:10 · Score: 1
  
  Unless the shoreline is made up of vertical cliffs. Then there would be no difference with the tides.
  
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3. Re:Tides... by mister_playboy · 2014-10-01 02:46 · Score: 4, Informative
  
  Titan is tidally locked to Saturn and does not experience tides like Earth's. Liquid bodies there would only be disturbed by weather or tectonics AFAIK.
  
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Imagine we would find the Solaris lifeform by Qbertino · 2014-09-30 23:30 · Score: 1

Imagine we would find a lifeform like in Lems' Solaris. Not many species but one single one occuping a planet.
A Super-Amobea that won the evolutionary race some hundred million years ago or something.
Would it have a conscience? If yes, what kind of conscience?
Would scientists discuss, wether it is ethical to take a probe or not? Would we be hurting a being? Would be deem it ethical (or not) to send probes into it/down there? ...
Interesting questions.
But then again, I'd say it's probably just land exposed and covered by tides.
Meeeh. Boooooring.

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The shore line IS changing. by Anonymous Coward · 2014-10-01 01:25 · Score: 1

The last image strongly shows that the entire regional shore line is changing, *not* just the island feature.
http://photojournal.jpl.nasa.gov/catalog/PIA18430
Looks like wave shoaling exposes the shallower water in the areas next to easily eroded land material.
http://en.wikipedia.org/wiki/Wave_shoaling
So maybe the entire basin is emptying and filling cyclically?
More data will tell the tale.
Re:it's R'lyeh by CauseBy · 2014-10-01 03:04 · Score: 1

I'm not saying it's aliens, but...
It's Methane Hydrate/Clathrate by RealGene · 2014-10-01 04:16 · Score: 1

You've got water ice and methane, you're gonna get hydrates. I'm guessing it boils off in the warm season.

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The island from Lost by PPH · 2014-10-01 05:29 · Score: 1

Now we know where it went to after the series ended.

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Re:Interesting... by dgatwood · 2014-10-01 06:16 · Score: 2

No, 1:16:9. Our entire solar system moved to high-def monoliths shortly after 2001.

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Re:Interesting... by Jeremiah+Cornelius · 2014-10-01 08:33 · Score: 1

No, 1:16:9. Our entire solar system moved to high-def monoliths shortly after 2001.
But local reception really degraded...

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