Amalthea

General discussion about Celestia that doesn't fit into other forums.
Avatar
Topic author
Anthony_B_Russo10
Posts: 292
Joined: 03.07.2018
Age: 16
With us: 1 year 5 months
Location: Tallahassee, Florida, US

Amalthea

Post #1by Anthony_B_Russo10 » 18.08.2018, 19:42

Amalthea in 1.2.4 looks better then...
Amalthea 2.png

...it does in NASA Eyes.
Amalthea.png
Anthony B. Russo, I like Pluto. Mod of the Celestia subreddit: https://www.reddit.com/r/Celestiasoftware/
Dell Latitude D820 D400 D410 D420 6520 D610, Acer Aspire, Dell Optiplex 745 x2 755 GX-620 960, Sony Vaio PCG-F420, Packard Bell Legend 100, HP Compaq, IBM clone, IBM ThinkPad, MacBook Pro

Avatar
SpaceFanatic64
Posts: 400
Joined: 16.08.2018
Age: 13
With us: 1 year 3 months
Location: Southern California

Post #2by SpaceFanatic64 » 19.08.2018, 04:37

The sad thing is that it's true. NASA should really start using better representations of small bodies. :sad:

Avatar
Topic author
Anthony_B_Russo10
Posts: 292
Joined: 03.07.2018
Age: 16
With us: 1 year 5 months
Location: Tallahassee, Florida, US

Post #3by Anthony_B_Russo10 » 01.09.2018, 19:14

Yeah.
Anthony B. Russo, I like Pluto. Mod of the Celestia subreddit: https://www.reddit.com/r/Celestiasoftware/
Dell Latitude D820 D400 D410 D420 6520 D610, Acer Aspire, Dell Optiplex 745 x2 755 GX-620 960, Sony Vaio PCG-F420, Packard Bell Legend 100, HP Compaq, IBM clone, IBM ThinkPad, MacBook Pro

Avatar
SevenSpheres
Posts: 141
Joined: 08.10.2019
With us: 1 month 29 days

What color is Amalthea?

Post #4by SevenSpheres » 01.12.2019, 23:23

I think this is fine in this year old thread, if not a mod can split it...

What's the correct color for Amalthea? It appears red in Voyager images, it's red in Celestia Origin as well as default Celestia, but in Project Echoes it's gray.

Amalthea_(moon).png
Amalthea_(moon).png (10.91 KiB) Viewed 168 times

amalthea-origin.png

amalthea-echoes.png
PC specs: HP desktop, Windows 10 Home 64-bit, Intel Core i7-7700 (3.60 GHz), 16 GB RAM, 1 TB HDD + 128 GB SSD, Intel HD Graphics 630
My Addons: viewtopic.php?f=23&t=19978 (the forum won't let me add a link here)

Avatar
Topic author
Anthony_B_Russo10
Posts: 292
Joined: 03.07.2018
Age: 16
With us: 1 year 5 months
Location: Tallahassee, Florida, US

Post #5by Anthony_B_Russo10 » 01.12.2019, 23:54

When I created this it was to point out an inaccuracy of NASA's Eyes.
Anthony B. Russo, I like Pluto. Mod of the Celestia subreddit: https://www.reddit.com/r/Celestiasoftware/
Dell Latitude D820 D400 D410 D420 6520 D610, Acer Aspire, Dell Optiplex 745 x2 755 GX-620 960, Sony Vaio PCG-F420, Packard Bell Legend 100, HP Compaq, IBM clone, IBM ThinkPad, MacBook Pro

Avatar
SevenSpheres
Posts: 141
Joined: 08.10.2019
With us: 1 month 29 days

Post #6by SevenSpheres » 02.12.2019, 00:08

Anthony_B_Russo10 wrote:When I created this it was to point out an inaccuracy of NASA's Eyes.

The thread's title is "Amalthea", not "Inaccuracies in NASA Eyes". My intent was to continue discussion about the appearance of Amalthea. Compare FarGetaNik's post here. As I said, if my post really shouldn't be here, a mod can split it.

I think replying to a year old thread about the appearance of Amalthea with a question about the appearance of Amalthea is very different from replying to a many years old thread about spectral types with "I think neutron stars might be green".
Last edited by SevenSpheres on 02.12.2019, 00:29, edited 1 time in total.
PC specs: HP desktop, Windows 10 Home 64-bit, Intel Core i7-7700 (3.60 GHz), 16 GB RAM, 1 TB HDD + 128 GB SSD, Intel HD Graphics 630
My Addons: viewtopic.php?f=23&t=19978 (the forum won't let me add a link here)

Avatar
Topic author
Anthony_B_Russo10
Posts: 292
Joined: 03.07.2018
Age: 16
With us: 1 year 5 months
Location: Tallahassee, Florida, US

Post #7by Anthony_B_Russo10 » 02.12.2019, 00:29

Well, we'll have to see what Lafuente_Astronomy thinks.
Anthony B. Russo, I like Pluto. Mod of the Celestia subreddit: https://www.reddit.com/r/Celestiasoftware/
Dell Latitude D820 D400 D410 D420 6520 D610, Acer Aspire, Dell Optiplex 745 x2 755 GX-620 960, Sony Vaio PCG-F420, Packard Bell Legend 100, HP Compaq, IBM clone, IBM ThinkPad, MacBook Pro

Avatar
Lafuente_Astronomy
Moderator
Posts: 470
Joined: 04.08.2018
Age: 21
With us: 1 year 4 months
Location: Cebu City, Cebu Province, Philippines
Contact:

Post #8by Lafuente_Astronomy » 02.12.2019, 22:36

SevenSpheres wrote:I think replying to a year old thread about the appearance of Amalthea with a question about the appearance of Amalthea is very different from replying to a many years old thread about spectral types with "I think neutron stars might be green".

In this particular case, you have justification for doing so. The intent is to give out some new and relevant information, and not to well, do something. It's a pass.

SevenSpheres wrote:The thread's title is "Amalthea", not "Inaccuracies in NASA Eyes"

Just because the title says one thing does not mean that the intention should be the same as the title. Maybe out of hurry, he entitled it that way though his intention was to make a comparison between Celestia and NASA Eyes. You should not think of the title very literally.
Official Administrator of the Celestia Discord Server.
Invite: https://discordapp.com/invite/WEWDcJh
If you don't have a Discord account, register here: https://discordapp.com/register
Have a blessed day.

Avatar
Joey P. M
Posts: 349
Joined: 28.10.2017
Age: 17
With us: 2 years 1 month
Location: Vladivostok, Russia

Post #9by Joey P. » 03.12.2019, 01:40

This should be in "Physics and Astronomy".
Joey P.

Avatar
SevenSpheres
Posts: 141
Joined: 08.10.2019
With us: 1 month 29 days

Post #10by SevenSpheres » 03.12.2019, 01:46

Joey P. wrote:This should be in "Physics and Astronomy".

Why? And can anyone answer my question about Amalthea's color?
PC specs: HP desktop, Windows 10 Home 64-bit, Intel Core i7-7700 (3.60 GHz), 16 GB RAM, 1 TB HDD + 128 GB SSD, Intel HD Graphics 630
My Addons: viewtopic.php?f=23&t=19978 (the forum won't let me add a link here)

Avatar
Joey P. M
Posts: 349
Joined: 28.10.2017
Age: 17
With us: 2 years 1 month
Location: Vladivostok, Russia

Post #11by Joey P. » 03.12.2019, 01:51

Amalthea is red; red is the color of old asteroids. And this should be in Physics and Astronomy because it isn't really about Celestia but rather NASA.
Joey P.

Avatar
Topic author
Anthony_B_Russo10
Posts: 292
Joined: 03.07.2018
Age: 16
With us: 1 year 5 months
Location: Tallahassee, Florida, US

Post #12by Anthony_B_Russo10 » 03.12.2019, 01:56

Well color images do commonly show Amalthea's color as red.
Anthony B. Russo, I like Pluto. Mod of the Celestia subreddit: https://www.reddit.com/r/Celestiasoftware/
Dell Latitude D820 D400 D410 D420 6520 D610, Acer Aspire, Dell Optiplex 745 x2 755 GX-620 960, Sony Vaio PCG-F420, Packard Bell Legend 100, HP Compaq, IBM clone, IBM ThinkPad, MacBook Pro

Avatar
fyr02
Posts: 134
Joined: 19.04.2019
Age: 14
With us: 7 months 18 days
Location: San Diego, California (United States)

Post #13by fyr02 » 03.12.2019, 02:39

except spectrum processing puts the color closer to yellow...

Joey P,
Galileo do indeed show Amalthea's color as red but Galileo images were not composed from RGB filters, the highest quality image was composed from OCV filters (orange, cyan, and violet).
I have my messed up origins; I can't control my mind. Also, did you know that cashews grow on top of apples?

Avatar
Joey P. M
Posts: 349
Joined: 28.10.2017
Age: 17
With us: 2 years 1 month
Location: Vladivostok, Russia

Post #14by Joey P. » 03.12.2019, 03:40

Oh...

But in my opinion I would use RGB color filters.
Joey P.

Avatar
FarGetaNik M
Posts: 476
Joined: 05.06.2012
With us: 7 years 6 months
Location: Germany

Post #15by FarGetaNik » 03.12.2019, 15:10

SevenSpheres wrote:And can anyone answer my question about Amalthea's color?

I did some research for Project Echoes on the color of various celestial objects, including Amalthea. Unfortunately, I couldn't find much useable data. Amalthea certainly reflects more red than blue light... but translating that into a color that a human eye would perceive is another question.

This is what i found:
Fig4_takato.gif


This spectrum only has 2 data points in the visible range, which is hardly sufficient to derive an 3 vector color for red, green and blue. I tried anyways and ended up with a yellowish-brown color, that when blended down to Amaltheas dark surface, appears almost grey to the human eye. So the answer is: Amalthea is brownish but appears dark grey. If anyone has a more detailed spectrum of Amalthea in the visible range I'd love to see and improve my color rendition for Amalthea.

Askaniy provided me with a list of color indices which lists a value for Amalthea of B-V = 1.5 which is comparable with some of the more red TNO, but since I can't find a value for V-R we can't tell if Amalthea is yellowish or reddish. One source compared Amaltheas color slope with that of Io and stated it was less red than Mars.

Avatar
Joey P. M
Posts: 349
Joined: 28.10.2017
Age: 17
With us: 2 years 1 month
Location: Vladivostok, Russia

Post #16by Joey P. » 03.12.2019, 23:28

So P-type asteroids are slightly green and C-type asteroids slightly blue but dark, right?
Joey P.

Avatar
Sirius_Alpha
Posts: 58
Joined: 21.03.2019
With us: 8 months 16 days

Post #17by Sirius_Alpha » 04.12.2019, 01:29

Joey P., the green and blue regions in the graph above only denote where the spectra of those asteroids tend to lie, not the actual colour of the asteroids. For all three asteroid spectral types, they are varying degrees of red (their brightness increases with wavelength). The higher the slope, the redder they are. C-type asteroids appear to be almost grey, having a flat spectrum.


Return to “Celestia Users”

Who is online