Celestia Forums

Hi all,

just before landing on Europa (8k texture), I came across this neat view...Thought I might share it:

Bye Fridger

Nice shot,

although Jupiter and Io is to red .

Bye Jens

PS: I have at the moment no better textures.

Fridger,

Would you be willing to share the Cel://URL for this viewpoint?

jim wrote:Nice shot,

although Jupiter and Io is to red .

Bye Jens

PS: I have at the moment no better textures.

Jens,

claims about incorrect colors are not very useful if you do not quote the corresponding scientific references...

Here is e.g. a shot from the Cassini spacecraft in 2001 showing the brown-red of jupi's bands together with a fairly red io. To my eyes the colors are not too different from my hires jupi texture above and/or io. The cassini shot is from NASA's photojournal/jupiter.

When I made the jupi texture some time ago, I have /carefully/ tuned the colors against the best available truecolor shot, I think it was a very recent Galileo image. Can't find it off hand, but the comparison is somewhere in the forum. The colors were almost indistinguishable.

So given that I put quite a bit of care into the coloring issue, your remarks can only be useful if they are quantified...

Bye Fridger

selden wrote:Fridger,

Would you be willing to share the Cel://URL for this viewpoint?

Oh, too bad,I should have quoted the cel://url together with the shot right away. Now I will not be able anymore, to reproduce the view point so easily...

Bye Fridger

Here's a version of Fridgers view but actually on the surface of Europa.

cel://SyncOrbit/Sol:Jupiter:Europa/2003-12-29T09:15:27.07427?x=6/szuw4pRxduDA&y=9WEsHyl376cB&z=RY/QlOVdYybh/////////w&ow=-0.251097&ox=0.658714&oy=0.656047&oz=0.269534&select=Sol:Jupiter:Europa&fov=10.231119&ts=1.000000<d=0&rf=40707&lm=128

Jens,

I found this recent Cassini-truecolor shot of jupi again. The comparison between my texture is below.
I think the pale-brown and brown-redish-orange tones are very close indeed,
yet there should be somewhat more blue in the cloud bands. This however is a matter of tuning the spectral color in solarsys.ssc.
Note that the clouds (mostly) in the central band of my texture are separate and moving,
hence their color adaptation is a separate issue from Jupi's base colors. Can you see the faint ring?

I think the best approach to quasi-perfection would be to rework the moving cloud bands a bit,
notably to make them bluer and add another one near the latitude of the "Red" spot!

The Cassini shot is at the bottom;-)

Bye Fridger

Hi Fridger,

There is not that clear proof what you want but many little pieces leads to my current thinking about but .

It was a while ago I searched for color infomation about Io, Mars and other bodys. NASA's photojournal is e very nice and large image source and has god notes to the images. By reading this and infos of other sites I had to learn several things.

Don't trust the colors of an image (also and especially on Nasa sites) if there is no exact information about it's creation!

There is (or can be) a differnce between true/real color and natural color. All the nice Galileo pictures are real color but not natural color. Real color does mean that real color data were used for the picture but the color space must be not that of the human eye. Galileo's imaging camera used several channels with different wavelength to composite an colore image. But there was no channel for blue and red. The spacecraft used near violet (410 nanometers) and infrared (756 nanometers) to get this colors. Therefore all this nice images from Galileo represent not natural colors (or what a human would see).

There are some rare picture on the Web that tries to shows how planets and moon approximate look in natural colors.
http://www.lpi.usra.edu/research/outerp/moons.html
http://www.donaldedavis.com/2002_addons/SSYCOLRS.html

Information about a natural colored Io allows conclutions to Jupiter.

This Voyager 1 picture comes close to my sight of things.
http://photojournal.jpl.nasa.gov/catalog/PIA00358


As I said at the begin this is not the clear proof you want.

Bye Jens

PS: My 4k Io map was made before I get this informations. I should revice this texture.

jim wrote:Hi Fridger,

There is not that clear proof what you want but many little pieces leads to my current thinking about but .

It was a while ago I searched for color infomation about Io, Mars and other bodys. NASA's photojournal is e very nice and large image source and has god notes to the images. By reading this and infos of other sites I had to learn several things.

Don't trust the colors of an image (also and especially on Nasa sites) if there is no exact information about it's creation!

There is (or can be) a differnce between true/real color and natural color. All the nice Galileo pictures are real color but not natural color. Real color does mean that real color data were used for the picture but the color space must be not that of the human eye. Galileo's imaging camera used several channels with different wavelength to composite an colore image. But there was no channel for blue and red. The spacecraft used near violet (410 nanometers) and infrared (756 nanometers) to get this colors. Therefore all this nice images from Galileo represent not natural colors (or what a human would see).

There are some rare picture on the Web that tries to shows how planets and moon approximate look in natural colors.
http://www.lpi.usra.edu/research/outerp/moons.html
http://www.donaldedavis.com/2002_addons/SSYCOLRS.html

Information about a natural colored Io allows conclutions to Jupiter.

This Voyager 1 picture comes close to my sight of things.
http://photojournal.jpl.nasa.gov/catalog/PIA00358


As I said at the begin this is not the clear proof you want.

Bye Jens

PS: My 4k Io map was made before I get this informations. I should revice this texture.

Jens,
you apparently have not read my last message well: The jupi truecolor image that I use is from /cassini / (NOT Galileo) and in the NASA description said to be the /best available/ truecolor image, matching the human eye view...That's why I chose that image. I simply have very little time right now and thus did not exactly remember, since I made my Jupi texture almost one year ago.

You "Citro-Jupi" just gives me showers;-), perhaps since I looked at jupiter too often through my telescope;-). This Citro color I leave to you, without "competition";-)

Bye Fridger

Jens:
Here's a link to the Cassini imaging website. Notice the red coloration of Jupiter on the left side of the fourth-from-last image, which is clearly marked as true (human eye) colour, and then follow through to the second-last image, which shows Jupiter in the same colours together with a distinctly orange Io.
http://ciclops.lpl.arizona.edu/ciclops/images_jupiter.html

Grant