APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Comments and questions about the APOD on the main view screen.
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APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby APOD Robot » Wed Oct 15, 2014 4:06 am

Image Mysterious Changing feature on Titan

Explanation: What is that changing object in a cold hydrocarbon sea of Titan? Radar images from the robotic Cassini spacecraft orbiting Saturn have been recording the surface of the cloud-engulfed moon Titan for years. When imaging the flat -- and hence radar dark -- surface of the methane and ethane lake called Ligeia Mare, an object appeared in 2013 just was not there in 2007. Subsequent observations in 2014 found the object remained -- but had changed! The featured image shows how the 20-km long object has appeared and evolved. Current origin speculative explanations include bubbling foam and floating solids, but no one is sure. Future observations may either resolve the enigma or open up more speculation.

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby bystander » Wed Oct 15, 2014 4:17 am

Know the quiet place within your heart and touch the rainbow of possibility; be
alive to the gentle breeze of communication, and please stop being such a jerk.
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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Nitpicker » Wed Oct 15, 2014 5:50 am

I've no idea what the changing feature might be on this strange world. But with Titan's axis very closely aligned with Saturn's axis, I should think that in 2007, Titan's northern polar region would have been on its way out from a long spell of darkness, whereas it is now in the beginning of a long spell of sunshine, admittedly only 1% of the sunshine Earth receives. So, I suppose it's tempting to call it a mysterious seasonal change.

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby madtom1999 » Wed Oct 15, 2014 7:37 am

Is it not possible to get some 3d type images of this.
Wondering if it could be tidal.

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby ems57fcva » Wed Oct 15, 2014 10:36 am

Look carefully at the overall image. There appears to be a line of demarcation in first two images running from the center of the top of teh frame towards the bottom near the lower left corner. There is more "stuff" to the right of that line than to the left. In the last picture, the line is still there, but it has moved to the right, and more so at the bottom than the top. Also the "stuff" on the right side of the line is brighter which I take to mean that it is denser.

I assume that the change in the location of the line is due to a change of current in Ligeia Mare. This in turn indicates that the "stuff" is floating.

Conclusion: The changing bright feature may be hydrocarbon "icebergs" getting caught on some shallows and then breaking up and/or moving on. That would explain why the feature was not observed in pictures between 7/13 and last August.

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Guest » Wed Oct 15, 2014 11:58 am

If you look carefully at the image, you will see a 'bay' to the right of the inscribed circle. And then a ridge that separates the next structure that looks like a fiord. Carefully compare the three images and you will see changes in the three images. Assuming these are fixed features of the 'landscape', then the logical conclusion is that the surface level of the lake has dropped over the two year period. Evaporation could account for that, but what of the process and timeframes?

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Tszabeau » Wed Oct 15, 2014 1:04 pm

There appears to be some craters, on the right side of the most recent image that are not so apparent in the earlier pics... or are my eyes playing tricks again?

Marv the obvious

Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Marv the obvious » Wed Oct 15, 2014 2:15 pm

Based on how the shoreline changes at the objects to the right of the object in question, I'd say some how the fluid level changed in the time span between the images, either by loss or tide.

Marvtheobvious

Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Marvtheobvious » Wed Oct 15, 2014 2:17 pm

Based on how the shoreline changes at the objects to the right of the object in question, I'd say some how the fluid level changed in the time span between the images, either by loss or tide.

julianm3

Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby julianm3 » Wed Oct 15, 2014 5:07 pm

Thar be whales on Titan!

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby MarkBour » Wed Oct 15, 2014 5:08 pm

I'm suspecting the third image may have a focal difference from the other two. If not, then the changes are happening much more rapidly than in the first 6 years. 'Tis a great set of images. Hopefully over time we'll learn about dissolution/condensation processes on very cold methane seas.
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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Boomer12k » Wed Oct 15, 2014 5:55 pm

Looks to me like there are LOTS of changes from left to right....too numerous to point out....

So...the place changes...it has a sea...an atmosphere...it is bound to be somewhat Dynamic....not the Static Universe some would suppose....

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby dlw » Wed Oct 15, 2014 5:56 pm

There seem to be quite a few changes. The most dramatic is, of course, the "island" but there are many others. I assume, since this is radar, that changes in lighting is not an explanation. Very interesting.

kindness

Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby kindness » Wed Oct 15, 2014 6:46 pm

Maybe this 'lake' has a tide.

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Kasuha » Wed Oct 15, 2014 6:57 pm

Looks like a tidal effect to me with some feature very close to the liquid surface appearing and disappearing periodically. The shoreline appears lower in the (bottom right part of) second image (since upper left is copied from first image), then it is back up in the third image.

I wonder how was the feature oriented relative to Saturn in either of the three cases.

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Startreader » Wed Oct 15, 2014 8:15 pm

APOD Robot wrote:Current origin speculative explanations include bubbling foam and floating solids, but no one is sure. Future observations may either resolve the enigma or open up more speculation.


The explanation is obvious: this is an image of a man driving a construction crane with his wiry little doggie in the left-hand seat. He has been bringing sand and stones and stuff to build a castle at the sea-shore. He's cold, so he's slow.

I say "man" not to be sexist but because most crane drives are male and "man" would include aliens. The shape is definitely a biped with two arms and a sensor stalk topped by a floppy cap. Possibly named "Bob".

Maxim

Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Maxim » Wed Oct 15, 2014 8:23 pm

It's in a hydrocarbon SEA. The tides come in....the tides go out. Shallows cover up.....shallows appear.

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Nitpicker » Thu Oct 16, 2014 1:56 am

Note that the upper part of the middle image -- above what I assume is the black "stitching" line on an angle -- is identical to the upper part of the left image. Looks like they didn't capture the full field of view in 2013. Most of the differences in the images can probably be explained away as noise, but not the mysterious feature inside the ellipse. (North is to the image bottom-left, by the way.)

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Ann » Thu Oct 16, 2014 3:56 am

Startreader wrote:
I say "man" not to be sexist but because most crane drives are male and "man" would include aliens.


Hey, I have no problem with your assumption that a crane driver would usually be a man, but... aren't there female aliens?

As Mr Spock once said, It is a well-known fact that we Vulcans propagate our race by mail. :wink:

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Perk Cartel » Thu Oct 16, 2014 4:00 am

I'm guessing "seasonal" ethane/methane cycle and/or tidal event affecting lake surface level relative to the lake edge terrain...

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Beyond » Thu Oct 16, 2014 4:53 am

Ann wrote:As Mr Spock once said, It is a well-known fact that we Vulcans propagate our race by mail. :wink:

I must have missed that episode.
To find the Truth, you must go Beyond.

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Ann » Thu Oct 16, 2014 5:20 am

Beyond wrote:
Ann wrote:As Mr Spock once said, It is a well-known fact that we Vulcans propagate our race by mail. :wink:

I must have missed that episode.


The Spock quote might have been in a Star Trek novel. I read tons of them in the 1980s. :oops:

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby Nitpicker » Thu Oct 16, 2014 6:42 am

Ann wrote:
Startreader wrote:
I say "man" not to be sexist but because most crane drives are male and "man" would include aliens.


Hey, I have no problem with your assumption that a crane driver would usually be a man, but... aren't there female aliens?

As Mr Spock once said, It is a well-known fact that we Vulcans propagate our race by mail. :wink:

Ann


Not logical, Ann. Startreader's comment does not rule out the possibility of female aliens. And I'm sure it's just a coincidence that the interval over which this APOD was recorded -- seven years -- is the same interval experienced by Vulcans, in between bouts of their mating cycle hormone imbalance, pon farr.

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby DavidLeodis » Thu Oct 16, 2014 12:57 pm

Seeing the image brought up through the "Future observations" link made me :).

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Re: APOD: Mysterious Changing feature on Titan (2014 Oct 15)

Postby DavidLeodis » Thu Oct 16, 2014 1:02 pm

Nitpicker wrote:Note that the upper part of the middle image -- above what I assume is the black "stitching" line on an angle -- is identical to the upper part of the left image. Looks like they didn't capture the full field of view in 2013. Most of the differences in the images can probably be explained away as noise, but not the mysterious feature inside the ellipse. (North is to the image bottom-left, by the way.)


Hi Nitpicker.

In the information brought up through the 'featured image' link it states "The upper half of the middle image uses data from the April 26, 2007 Titan flyby. That area did not receive SAR coverage during the July 10, 2013 encounter, so the earlier data was used to fill-in the scene."


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