Welcome to DU! The truly grassroots left-of-center political community where regular people, not algorithms, drive the discussions and set the standards. Join the community: Create a free account Support DU (and get rid of ads!): Become a Star Member All Forums Issue Forums Culture Forums Alliance Forums Region Forums Support Forums Help & Search

Ichingcarpenter

(36,988 posts)
Thu Mar 5, 2015, 05:34 AM Mar 2015

Phobos silhouetted against the Martian surface. Photo from the Mars Orbiter Mission spacecraft





Anyone know why the limb of Mars looks green/blueish here, but in the other photo of Mars' limb, it looks like the usual reddish color?
Is one true color, and the other is false?
11 replies = new reply since forum marked as read
Highlight: NoneDon't highlight anything 5 newestHighlight 5 most recent replies
Phobos silhouetted against the Martian surface. Photo from the Mars Orbiter Mission spacecraft (Original Post) Ichingcarpenter Mar 2015 OP
Cool! Sherman A1 Mar 2015 #1
Awesome Bugenhagen Mar 2015 #2
I swear, if this turns into a "What color is this planet?" thing... JHB Mar 2015 #3
I see white/gold. nt stillwaiting Mar 2015 #4
I see that too but Ichingcarpenter Mar 2015 #5
It is a weird photo. Now I see black/blue. nt stillwaiting Mar 2015 #6
The original image seems to be here on the ISRO website.... xocet Mar 2015 #7
Backscattering of light modrepub Mar 2015 #8
The Martian atmosphere scatters blue light, too. n/t Orsino Mar 2015 #9
Fantastic photo! trusty elf Mar 2015 #10
That looks so fake nikto Mar 2015 #11

xocet

(3,870 posts)
7. The original image seems to be here on the ISRO website....
Thu Mar 5, 2015, 01:42 PM
Mar 2015
Indian Space Research Organization
Mars Orbiter Mission

http://www.isro.gov.in/pslv-c25-mars-orbiter-mission


Maybe they (the ISRO) would be able to answer your question.

modrepub

(3,468 posts)
8. Backscattering of light
Thu Mar 5, 2015, 03:32 PM
Mar 2015

If the colors are true then what you may be seeing is backscattering in the Martian atmosphere. The Martian atmosphere is actually viewable in this picture; it's the transparent layer along the edge of the planet. Molecular backscattering on Mars is similar to earth with blue colors being preferentially scattered thus giving the blue sky you see when the sun is out on a clear day (at least directly overhead). I'd probably add that there tends to be a lot of dust in the Martian atmosphere, which also scatters light, and can also be contributing to the colors you are seeing in this image, again if it's not a false color image. If you look at some of the old Viking probe surface images the Martian sky does appear to be blue, similar to Earth.

Latest Discussions»Culture Forums»Science»Phobos silhouetted agains...