APOD: Seeing Titan (2020 Aug 20)

Comments and questions about the APOD on the main view screen.
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APOD: Seeing Titan (2020 Aug 20)

Post by APOD Robot » Thu Aug 20, 2020 4:05 am

[img]https://apod.nasa.gov/apod/calendar/S_200820.jpg[/img] Seeing Titan

Explanation: Shrouded in a thick atmosphere, Saturn's largest moon Titan really is hard to see. Small particles suspended in the upper atmosphere cause an almost impenetrable haze, strongly scattering light at visible wavelengths and hiding Titan's surface features from prying eyes. But Titan's surface is better imaged at infrared wavelengths where scattering is weaker and atmospheric absorption is reduced. Arrayed around this visible light image (center) of Titan are some of the clearest global infrared views of the tantalizing moon so far. In false color, the six panels present a consistent processing of 13 years of infrared image data from the Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini spacecraft. They offer a stunning comparison with Cassini's visible light view.

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Re: APOD: Seeing Titan (2020 Aug 20)

Post by neufer » Thu Aug 20, 2020 4:38 am

https://en.wikipedia.org/wiki/Tantalus wrote:
<<Welcomed to Jupiter's table in Olympus Tantalus is said to have abused Jupiter's hospitality and stolen ambrosia and nectar to bring it back to his people, and revealed the secrets of the gods. Tantalus's punishment for his act, now a proverbial term for temptation without satisfaction (the source of the English word tantalize), was to stand in a pool of water beneath a fruit tree with low branches. Whenever he reached for the fruit, the branches raised his intended meal from his grasp. Whenever he bent down to get a drink, the water receded before he could get any. Over his head towers a threatening stone like the one that Sisyphus is punished to roll up a hill.

The Greeks used the proverb "Tantalean punishments" (Ancient Greek: Ταντάλειοι τιμωρίαι), in reference to those who have good things but are not permitted to enjoy them.>>
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Re: APOD: Seeing Titan (2020 Aug 20)

Post by A vent » Thu Aug 20, 2020 4:49 am

Looks like a ball of molten metal covered in flux and impurities. Junk. But one man's junk is another man's treasure. To bad we can't refine the thing.

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Re: APOD: Seeing Titan (2020 Aug 20)

Post by neufer » Thu Aug 20, 2020 5:12 am

A vent wrote:
Thu Aug 20, 2020 4:49 am

Looks like a ball of molten metal covered in flux and impurities. Junk.
But one man's junk is another man's treasure. To bad we can't refine the thing.
The Greeks used the proverb "Tantalean punishments" (Ancient Greek: Ταντάλειοι τιμωρίαι),
in reference to those who have good things but are not permitted to enjoy them.
Art Neuendorffer

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Re: APOD: Seeing Titan (2020 Aug 20)

Post by Ann » Thu Aug 20, 2020 5:12 am


Oh, Titan Titan, why Art thou so cold (94 K)?

Shouldn't you get dressed at least?

Ann
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LMMdT

Re: APOD: Seeing Titan (2020 Aug 20)

Post by LMMdT » Thu Aug 20, 2020 6:26 am

Nice marbles!

Alex_515

Re: APOD: Seeing Titan (2020 Aug 20)

Post by Alex_515 » Thu Aug 20, 2020 8:18 am

The white parts in the infrared pictures are methane clouds, right ?

heehaw

Re: APOD: Seeing Titan (2020 Aug 20)

Post by heehaw » Thu Aug 20, 2020 9:36 am

To think that it was only 365 years ago, that Christiaan Huygens, through his little telescope, discovered Titan - first moon of Saturn to be discovered!

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Re: APOD: Seeing Titan (2020 Aug 20)

Post by Boomer12k » Thu Aug 20, 2020 9:46 am

At first I thought it was a SUN... with exoplanets, or something...even MARS... then I read the article... now my pariedola is kicking in as I see rabbits, deer, a kangaroo all in one... Majin Buu from Dragonball Z... and "My Pretty Pony"... my god... I have it bad... :shock:

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Re: APOD: Seeing Titan (2020 Aug 20)

Post by Chris Peterson » Thu Aug 20, 2020 1:00 pm

Boomer12k wrote:
Thu Aug 20, 2020 9:46 am
At first I thought it was a SUN... with exoplanets, or something...even MARS... then I read the article... now my pariedola is kicking in as I see rabbits, deer, a kangaroo all in one... Majin Buu from Dragonball Z... and "My Pretty Pony"... my god... I have it bad... :shock:

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Please, please... as astronomers run out of mythological names for objects and structures, let us not fall back on My Pretty Pony!
Chris

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Re: APOD: Seeing Titan (2020 Aug 20)

Post by Chris Peterson » Thu Aug 20, 2020 1:01 pm

Ann wrote:
Thu Aug 20, 2020 5:12 am

Oh, Titan Titan, why Art thou so cold (94 K)?

Shouldn't you get dressed at least?
The artist has judiciously chosen a viewpoint that prevents us from determining just how cold Titan actual is...
Chris

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Re: APOD: Seeing Titan (2020 Aug 20)

Post by neufer » Thu Aug 20, 2020 1:32 pm

heehaw wrote:
Thu Aug 20, 2020 9:36 am

To think that it was only 365 years ago, that Christiaan Huygens, through his little telescope, discovered Titan - first moon of Saturn to be discovered!
  • Christiaan Huygens' little telescope :?: :arrow:
https://en.wikipedia.org/wiki/Titan_(moon)#Observation_and_exploration wrote:
<<In 1907 Spanish astronomer Josep Comas i Solà observed limb darkening of Titan, the first evidence that the body has an atmosphere. In 1944 Gerard P. Kuiper used a spectroscopic technique to detect an atmosphere of methane.

The first probe to visit the Saturnian system was Pioneer 11 in 1979, which revealed that Titan was probably too cold to support life. It took images of Titan, including Titan and Saturn together in mid to late 1979. The quality was soon surpassed by the two Voyagers.

Titan was examined by both Voyager 1 and 2 in 1980 and 1981, respectively. Voyager 1's trajectory was designed to provide an optimized Titan flyby, during which the spacecraft was able to determine the density, composition, and temperature of the atmosphere, and obtain a precise measurement of Titan's mass. Atmospheric haze prevented direct imaging of the surface, though in 2004 intensive digital processing of images taken through Voyager 1's orange filter did reveal hints of the light and dark features now known as Xanadu and Shangri-la, which had been observed in the infrared by the Hubble Space Telescope. Voyager 2, which would have been diverted to perform the Titan flyby if Voyager 1 had been unable to, did not pass near Titan and continued on to Uranus and Neptune.>>
.....................................................................
To think that it was only 40 years ago, that NASA was willing to risk the unprecedented Grand Tour of Uranus & Neptune by both Voyager spacecraft in order to observe a hazy orange fuzz ball :arrow:
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Re: APOD: Seeing Titan (2020 Aug 20)

Post by orin stepanek » Thu Aug 20, 2020 1:32 pm

PIA21923_fig1SeeingTitan1024.jpg

I like these pictures of Titan; Kinda looks like continents on this world! 😍 8-)
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Re: APOD: Seeing Titan (2020 Aug 20)

Post by neufer » Thu Aug 20, 2020 1:36 pm

Click to play embedded YouTube video.
Chris Peterson wrote:
Thu Aug 20, 2020 1:01 pm
Ann wrote:
Thu Aug 20, 2020 5:12 am

Oh, Titan Titan, why Art thou so cold (94 K)?

Shouldn't you get dressed at least?
The artist has judiciously chosen a viewpoint that prevents us from determining just how cold Titan actual is...
  • It's frightened turtles all the way down.
Art Neuendorffer

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Re: APOD: Seeing Titan (2020 Aug 20)

Post by Interested Observer » Fri Aug 21, 2020 7:48 am

It would help if the images included a legend regarding the colors used. They are false-colored but give no indication as to what each color represents. Are the orange areas liquid and the bluish-white areas solid? Or, is it vice-versa? What about the dark areas? Nice pix but, they don't mean much if you have no idea what you're seeing. :?

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Re: APOD: Seeing Titan (2020 Aug 20)

Post by bystander » Fri Aug 21, 2020 2:23 pm

Interested Observer wrote:
Fri Aug 21, 2020 7:48 am

It would help if the images included a legend regarding the colors used. They are false-colored but give no indication as to what each color represents. Are the orange areas liquid and the bluish-white areas solid? Or, is it vice-versa? What about the dark areas? Nice pix but, they don't mean much if you have no idea what you're seeing. :?

Not sure it will help, but...
APOD Robot wrote:
Thu Aug 20, 2020 4:05 am

Explanation: ... In false color, the six panels present a consistent processing of 13 years of infrared image data from the Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini spacecraft. They offer a stunning comparison with Cassini's visible light view.
PIA21923: Seeing Titan with Infrared Eyes wrote: ...
Any full color image is comprised of three color channels: red, green and blue. Each of the three color channels combined to create these views was produced using a ratio between the brightness of Titan's surface at two different wavelengths (1.59/1.27 microns [red], 2.03/1.27 microns [green] and 1.27/1.08 microns [blue]). This technique (called a "band-ratio" technique) reduces the prominence of seams, as well as emphasizing subtle spectral variations in the materials on Titan's surface. For example, the moon's equatorial dune fields appear a consistent brown color here. There are also bluish and purplish areas that may have different compositions from the other bright areas, and may be enriched in water ice. ...

Basically, I don't think they really know what it means.
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Re: APOD: Seeing Titan (2020 Aug 20)

Post by Chris Peterson » Fri Aug 21, 2020 2:39 pm

bystander wrote:
Fri Aug 21, 2020 2:23 pm
Interested Observer wrote:
Fri Aug 21, 2020 7:48 am

It would help if the images included a legend regarding the colors used. They are false-colored but give no indication as to what each color represents. Are the orange areas liquid and the bluish-white areas solid? Or, is it vice-versa? What about the dark areas? Nice pix but, they don't mean much if you have no idea what you're seeing. :?

Not sure it will help, but...
APOD Robot wrote:
Thu Aug 20, 2020 4:05 am

Explanation: ... In false color, the six panels present a consistent processing of 13 years of infrared image data from the Visual and Infrared Mapping Spectrometer (VIMS) on board the Cassini spacecraft. They offer a stunning comparison with Cassini's visible light view.
PIA21923: Seeing Titan with Infrared Eyes wrote: ...
Any full color image is comprised of three color channels: red, green and blue. Each of the three color channels combined to create these views was produced using a ratio between the brightness of Titan's surface at two different wavelengths (1.59/1.27 microns [red], 2.03/1.27 microns [green] and 1.27/1.08 microns [blue]). This technique (called a "band-ratio" technique) reduces the prominence of seams, as well as emphasizing subtle spectral variations in the materials on Titan's surface. For example, the moon's equatorial dune fields appear a consistent brown color here. There are also bluish and purplish areas that may have different compositions from the other bright areas, and may be enriched in water ice. ...

Basically, I don't think they really know what it means.
I'm pretty sure they do. https://www.researchgate.net/publicatio ... color_maps
Chris

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Re: APOD: Seeing Titan (2020 Aug 20)

Post by bystander » Fri Aug 21, 2020 3:06 pm

Chris Peterson wrote:
Fri Aug 21, 2020 2:39 pm
I'm pretty sure they do. https://www.researchgate.net/publicatio ... color_maps
Ok, they got a map, a pretty one, too, but what does it mean? I'm sure they are confident they have a good image of the surface features of Titan, but at the time of the map, did they really know what those features represent? Do they really know, even now?
Know the quiet place within your heart and touch the rainbow of possibility; be
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Re: APOD: Seeing Titan (2020 Aug 20)

Post by Chris Peterson » Fri Aug 21, 2020 3:12 pm

bystander wrote:
Fri Aug 21, 2020 3:06 pm
Chris Peterson wrote:
Fri Aug 21, 2020 2:39 pm
I'm pretty sure they do. https://www.researchgate.net/publicatio ... color_maps
Ok, they got a map, a pretty one, too, but what does it mean? I'm sure they are confident they have a good image of the surface features of Titan, but at the time of the map, did they really know what those features represent? Do they really know, even now?
The paper discusses the significance of the different ratios, in terms of water, methane, clouds, and other features.
Chris

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Re: APOD: Seeing Titan (2020 Aug 20)

Post by bystander » Fri Aug 21, 2020 3:36 pm

Chris Peterson wrote:
Fri Aug 21, 2020 3:12 pm
bystander wrote:
Fri Aug 21, 2020 3:06 pm
Chris Peterson wrote:
Fri Aug 21, 2020 2:39 pm
I'm pretty sure they do. https://www.researchgate.net/publicatio ... color_maps
Ok, they got a map, a pretty one, too, but what does it mean? I'm sure they are confident they have a good image of the surface features of Titan, but at the time of the map, did they really know what those features represent? Do they really know, even now?
The paper discusses the significance of the different ratios, in terms of water, methane, clouds, and other features.
What I read said there were different interpretations possible and that wasn't the purpose of these maps ...
The Cassini VIMS archive of Titan wrote:...
However, we point out that this interpretation is not unique ... Discriminating between these compositional signatures will require a very precise atmospheric removal and analysis of the detailed spectral structure within each window ... Our main objective here was rather to show the global distribution of spectral heterogeneities itself. We leave the identification of individual constituents to further dedicated studies ...
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.
— Garrison Keillor