APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

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Expand view Topic review: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by alter-ego » Thu Aug 01, 2013 6:03 am

neufer wrote:
Boomer12k wrote:
I am sorry....but if the SUN is on the other side of TITAN...then what we have IS a Solar Eclipse....just not an EARTH Solar Eclipse...But I guess it is argued that we are only looking at sunlight through the atmosphere of Titan....fine....don't call it an eclipse....but if the Moon had an Atmosphere, you would see a similar thing...and it would still be an eclipse....Scientists....Titan is still IN Eclipse....
"Since the image was taken pointing nearly at the Sun"
the Sun is NOT behind Titan but rather slightly off to the bottom right (and out of frame).
So the photo was taken June 10, 2006, ~15:40 UTC. The Solar System Simulator displays a nice prediction of the view of Titan and Enceladus (right). Physically, Enceladus is closer to Cassini than the rings. The bottom Stellarium simulation is a view from Enceladus. Although spacecraft Cassini does not exist in Stellarium, the line of sight from Enceladus to Titan is close to Cassini's, and therefore the Sun's location relative to the APOD is accurately represented. The Sun is located almost 20° from Titan, a little more than the tilt of the rings wrt the Sun (17.1°)
APOD<br /> 
APOD
 
 
 
Wider Angle Simulator View from Cassini<br />Titan is 3.3 arcminutes<br /> <br /> <br /> 
Wider Angle Simulator View from Cassini
Titan is 3.3 arcminutes
 
 
 
 
 
 
 
Stellarium View towards Titan from Enceladus<br />           Sun is ≈20° away from Titan
Stellarium View towards Titan from Enceladus
Sun is ≈20° away from Titan

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Chris Peterson » Tue Jul 30, 2013 9:26 pm

DavidLeodis wrote:Thanks Chris. :)

In a post of yours you state "I see it quite readily on my monitor, although it's subtle enough I'd probably miss it without it's being pointed out.". I am a bit surprised that you can readily see it. I can easily see all the different shades from black through to white in the grey shade bar so that does not seem to be the reason why I cannot see the jets, so the obvious inference is that the definition of my monitor is poor (or yours is much better :) ).
I do a lot of image processing, and have pretty high end display equipment, which I keep calibrated. And the jets are only a couple of percent brighter than the background. It might just be practice, too, given the amount of time I spend scrutinizing faint detail on a computer screen.

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by DavidLeodis » Tue Jul 30, 2013 8:32 pm

Thanks Chris. :)

In a post of yours you state "I see it quite readily on my monitor, although it's subtle enough I'd probably miss it without it's being pointed out.". I am a bit surprised that you can readily see it. I can easily see all the different shades from black through to white in the grey shade bar so that does not seem to be the reason why I cannot see the jets, so the obvious inference is that the definition of my monitor is poor (or yours is much better :) ).

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Beyond » Tue Jul 30, 2013 8:32 pm

well, apparently only in the black. All the rest of the graph is very distinguishable.

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Chris Peterson » Tue Jul 30, 2013 8:10 pm

Beyond wrote:After playing around with the settings for a while, i figure it's not worth the effort to be barely able to see a little jet that I've already seen in other photos. So i hit auto set. Life is much simpler with an auto-set, and ya don't miss much. :mrgreen:
You might be surprised how much you're missing, if you could only see it...

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by geckzilla » Tue Jul 30, 2013 8:00 pm

This is why we can't have nice things.

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Beyond » Tue Jul 30, 2013 7:45 pm

After playing around with the settings for a while, i figure it's not worth the effort to be barely able to see a little jet that I've already seen in other photos. So i hit auto set. Life is much simpler with an auto-set, and ya don't miss much. :mrgreen:

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by geckzilla » Tue Jul 30, 2013 7:16 pm

Make sure you don't overdo it, too. You want the three dark boxes to have just barely perceptible differences.

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Chris Peterson » Tue Jul 30, 2013 7:08 pm

Beyond wrote:The 3 black squares on the left look to be one black rectangle on my monitor.
In the absence of a calibrator, you may be able to adjust the brightness and contrast settings for your monitor to bring the background up. LCD monitors tend to have less control in that area, but most offer some. Try your display settings, as well. Depending on your operating system and display adapter, you may have the ability to tweak your brightness settings for all three color channels- basically, to make a custom color profile for your monitor. Make sure you have installed the color profile that came with your monitor (or can be downloaded). Lots of people skip doing that, but it can make a big improvement over the generic sRGB profile.

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Beyond » Tue Jul 30, 2013 6:01 pm

The 3 black squares on the left look to be one black rectangle on my monitor.

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Chris Peterson » Tue Jul 30, 2013 5:27 pm

DavidLeodis wrote:In the explanation to the image it states "Now if you look really really closely at Enceladus, you can see a hint of icy jets shooting out toward the bottom of the image". I would seem therefore to need a new monitor, as I cannot see the jets even on enlarging the image nor in the higher resolution TIFF image that can be brought up through the "Pictured above" link in the explanation. I suspect that most (if not all) people who may claim to see the jets in the APOD image would not have done so if they had not been told that they are there.
I see it quite readily on my monitor, although it's subtle enough I'd probably miss it without it's being pointed out.
graybar_g20.gif
graybar_g20.gif (1.06 KiB) Viewed 2483 times
You should easily be able to see each transition in this step chart. Particularly important are the 5% steps between the end pairs (the rest are 10% steps). If you can't, and accurate color is important to you, consider getting a monitor calibrator (of course, low end monitors are inherently limited).

Unfortunately, as is often the case with APOD images, there is no color management information in the Saturn image, so it will generally not look accurate in your browser, or in most image display programs.

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Beyond » Tue Jul 30, 2013 11:30 am

I couldn't see the jets either.

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by DavidLeodis » Tue Jul 30, 2013 11:20 am

In the explanation to the image it states "Now if you look really really closely at Enceladus, you can see a hint of icy jets shooting out toward the bottom of the image". I would seem therefore to need a new monitor, as I cannot see the jets even on enlarging the image nor in the higher resolution TIFF image that can be brought up through the "Pictured above" link in the explanation. I suspect that most (if not all) people who may claim to see the jets in the APOD image would not have done so if they had not been told that they are there.

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by retrogalax » Tue Jul 30, 2013 12:42 am

The Saturn's rings are so thin and stretched and Titan looks so big, Extraordinary :o

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Anthony Barreiro » Mon Jul 29, 2013 9:13 pm

The Cassini imaging team does it again! If we ever develop space tourism, I want to go fly around Saturn, the rings, and the moons.

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by PatMc » Mon Jul 29, 2013 3:59 pm

geckzilla wrote:
Guest wrote:I very much like the lines and tone of this image. Wish the linked-to full image was larger (I save many for use as a rotating desktop background).

Wondering there are larger versions somewhere?
There isn't a larger version but there is an uncompressed TIFF available: http://photojournal.jpl.nasa.gov/catalog/PIA08235
The raw photo just isn't huge to begin with. Ugh, the APOD image is pretty low quality, though. The jpg compression is way too high (or is it low?) and it destroys the details in the darkness such as the jets being emitted from Enceladus. I highly recommend having a look at the TIFF file from the above link even though it's clearly not large enough for a desktop background.

Thanks much; found that, fiddled with it a bit to get a larger version. Agreed that the minimal data means loss of clarity, but that fuzziness might just be what my old eyes need to see it clearly!

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by geckzilla » Mon Jul 29, 2013 3:41 pm

Guest wrote:I very much like the lines and tone of this image. Wish the linked-to full image was larger (I save many for use as a rotating desktop background).

Wondering there are larger versions somewhere?
There isn't a larger version but there is an uncompressed TIFF available: http://photojournal.jpl.nasa.gov/catalog/PIA08235
The raw photo just isn't huge to begin with. Ugh, the APOD image is pretty low quality, though. The jpg compression is way too high (or is it low?) and it destroys the details in the darkness such as the jets being emitted from Enceladus. I highly recommend having a look at the TIFF file from the above link even though it's clearly not large enough for a desktop background.

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Guest » Mon Jul 29, 2013 3:33 pm

I very much like the lines and tone of this image. Wish the linked-to full image was larger (I save many for use as a rotating desktop background).

Wondering there are larger versions somewhere?

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by neufer » Mon Jul 29, 2013 3:24 pm

Beyond wrote:
Boomer12k, the giveaway to where the sun is, is the shape of the ring of light around Titan. You'll notice that the brightest thickest part is around the 5 O'clock position. Because the ring of light is uneven around Titan, you know that the sun is not behind it.
  • Because the ring of light is uneven around Titan,
    you know that the sun is not directly behind it.

    It could still be a Diamond Ring situation, however.

    Note: The lighting on Enceladus is far more telling.

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Beyond » Mon Jul 29, 2013 1:01 pm

Boomer12k, the giveaway to where the sun is, is the shape of the ring of light around Titan. You'll notice that the brightest thickest part is around the 5 O'clock position. Because the ring of light is uneven around Titan, you know that the sun is not behind it.

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Boomer12k » Mon Jul 29, 2013 12:20 pm

neufer wrote:
Boomer12k wrote:
I am sorry....but if the SUN is on the other side of TITAN...then what we have IS a Solar Eclipse....just not an EARTH Solar Eclipse...But I guess it is argued that we are only looking at sunlight through the atmosphere of Titan....fine....don't call it an eclipse....but if the Moon had an Atmosphere, you would see a similar thing...and it would still be an eclipse....Scientists....Titan is still IN Eclipse....
"Since the image was taken pointing nearly at the Sun"
the Sun is NOT behind Titan but rather slightly off to the bottom right (and out of frame).

OH.....OK....It is a CRESCENT TITAN!!!! I GET IT!!!! They could have said so for us dummies....

As for "Follow The Water"....I agree....I am sure we will also explore Titan...One Rocket....Two Missions....Two Destinations...

Thanks for pointing out where the Sun is in the picture!!!

:---[===] *

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by neufer » Mon Jul 29, 2013 11:08 am

Boomer12k wrote:
I am sorry....but if the SUN is on the other side of TITAN...then what we have IS a Solar Eclipse....just not an EARTH Solar Eclipse...But I guess it is argued that we are only looking at sunlight through the atmosphere of Titan....fine....don't call it an eclipse....but if the Moon had an Atmosphere, you would see a similar thing...and it would still be an eclipse....Scientists....Titan is still IN Eclipse....
"Since the image was taken pointing nearly at the Sun"
the Sun is NOT behind Titan but rather slightly off to the bottom right (and out of frame).

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Boomer12k » Mon Jul 29, 2013 7:19 am

I am sorry....but if the SUN is on the other side of TITAN...then what we have IS a Solar Eclipse....just not an EARTH Solar Eclipse...But I guess it is argued that we are only looking at sunlight through the atmosphere of Titan....fine....don't call it an eclipse....but if the Moon had an Atmosphere, you would see a similar thing...and it would still be an eclipse....Scientists....Titan is still IN Eclipse....

Wonderful shot... Cassini always does an awesome job...

:---[===] *

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by neufer » Mon Jul 29, 2013 5:38 am

Ann wrote:
I thought it was Titan that was 64% Earthlike, so that Titan would be the prime target for exploration if humans ever go to Saturn to look for life?

Re: APOD: Saturn, Titan, Rings, and Haze (2013 Jul 29)

by Ann » Mon Jul 29, 2013 5:10 am

That is an impressive image of three phenomena that are unique to the Saturnian system: Saturn's mighty rings, Titan's thick atmosphere, and Enceladus' jets.
APOD Robot wrote:
It is these jets that inspired future proposals to land on Enceladus, burrow into the ice, and search for signs of extraterrestrial life.
I thought it was Titan that was 64% Earthlike, so that Titan would be the prime target for exploration if humans ever go to Saturn to look for life?

Ann

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