Color of the sky on Mars - Pink, blue, or green even?

Byron · 2002-07-22 05:33:39

I've been checking out some of the old Viking images that have been re-released, and I've noticed that the sky is blue in some of the photos, and in one instance, it actually had a green tint to it. So, do any of you out there know what the color of the Martian sky is "supposed" to be?

My theory is that the dust lofted high into the atmosphere is what causes the sky to have its "traditional" salmon color, but sometimes the atmosphere becomes devoid of suspended dust particles, which would give the sky an Earth-like hue on occasion. *Or*...these images have been digitally processed to the extent we don't have a clue to what the Martian sky really looks like...lol..

B

Nirgal82 · 2002-07-22 09:58:57

"My theory is that the dust lofted high into the atmosphere is what causes the sky to have its "traditional" salmon color, but sometimes the atmosphere becomes devoid of suspended dust particles, which would give the sky an Earth-like hue on occasion. *Or*...these images have been digitally processed to the extent we don't have a clue to what the Martian sky really looks like...lol.."

Hello Byron,
You aren't too far off from the simple fact, we don't know the true colors.
Well from what I've learned over the past couple of years looking at photos and panoramics of Mars, that you really can't be sure of anything about the color of the planet, sky or ground...
From what I can gather, all, and I do mean all photos of Mars taken by spacecraft are taken in monochromatic, just black and white. Then back at home, using techniques I'm not familliar with, processes the photos due to predetermined color keys. (I think they sent with the Viking Landers a panel that faced the cameras that had a simple pattern of colors, in the photos I've seen they are red, blue, and yellow) Not even the hubble takes color images. (this explains why Mars looks waaaaay redder in Hubble's eye than it did through the Viking orbiter)
I'm not sure what the reasons for this are, but we're stuck with it.
As for the color of Mars's sky, I've heard that computer models suggest it would have that pinkish hue from the horizon to about halfway up towards the zenith, from which point it would suddenly deepen to a dark blue (or blend into it with that greenish hue) where the closer to the zenith you look the darker it gets, and at the zenith itself and a ways around it the bighter stars and planets can be seen, unless the sun is there at the time in which case beyond its glareit would still be the deep blue. (although blue is earthlike, i think its the elements in the sky here that make the color, however on Mars the color change is due to the lack of air)
Of course on days where the dust is not in the sky the blue may go right to the horizon, or that green hue may perisist in place of the dust...

Your friendly neighborhood Martian...
-Matt

Ryjaz · 2002-07-22 10:57:28

I believe pathfinder had a color camera. Take a look at some of the pictures at JPL's Mars Pathfinder Homepage

It looks a little brownish to me.

Phobos · 2002-07-22 20:26:31

All that suspended dust in the atmosphere is one of things about Mars that drives me a little nuts. It would be depressing to look up and not be able to see a night sky full of stars. Hopefully the density of the dust is such that it won't block a whole lot of stars, hopefully Earth will still shine through. I think the astronauts should take a telescope along with them and take some CCD images of Earth so amateur astronomers can get some feel for what it would be like to stare back at Earth from Mars. With a 6" scope would you be able to resolve the ice caps and continents against the blue ocean? I don't own a telescope yet so I couldn't even fathom an answer.

Nirgal82 · 2002-07-22 20:32:37

Phobos, don't worry.
Mars will have spectacular night skies...
The zenith will always have stars to view, even during the day, so as for worrying about seing earth, it outta be the brightest object after your namesake, Phobos, and Deimos.
I've heard you'll even be able to make out the moon with the naked eye. although it just might be a whitish bump on the edge of the earth, assuming it is at the appropriate place in it's orbit.
Mars ought to have the finest skies known beyond Luna, with no atmosperic shiver like there is here...

Your friendly neighborhood Martian
-Matt

Shaun Barrett · 2002-07-23 05:55:49

Pssst! ... Pssst! ... C'm'ere!! Wanna hear a conspiracy theory?
Rumour has it that when the first surface pictures came in from Viking 1, with the red/green/blue adjustment in neutral, the terrain was a sandy brown colour and the sky was a pleasant shade of pale blue near the horizon. You wouldn't have known it from a rocky desert scene on Earth.
Next thing, somebody jumped up and turned the red adjustment up to full saturation. The scenery changed to the lurid red we've come to accept and the sky turned pink!
Apparently a couple of the original-colour pictures made it into circulation but were dismissed by NASA as being prematurely released before the "correct" colour saturation adjustments had been made.
Good conspiracy theory, huh?! Apart from the obvious question, of course. Why? Why would NASA want the surface of Mars to look more forbidding than it really is? Why would they try to hide a Mars with more Earth-like colourings, including a reassuringly blue sky?
I have no sensible answer to these questions.
But one thing does bother me a little bit: Have a look at the American flag on the lander in some of the "properly adjusted" pictures (properly adjusted, that is, according to NASA). The blue background behind the stars looks purple to me .... as though the red-gain is turned up too high!!
:0

Palomar · 2002-07-23 13:37:17

Phobos: All that suspended dust in the atmosphere is one of things about Mars that drives me a little nuts. It would be depressing to look up and not be able to see a night sky full of stars. Hopefully the density of the dust is such that it won't block a whole lot of stars, hopefully Earth will still shine through.

*Hmmmm, good point. It could be emotionally demoralizing as well, similar to very foggy days or long periods of overcast skies here on Earth. It'd also be depressing to mostly see the sun as a sand-blurred smudge of light day after day. They won't have any weather on Mars except for wind; no clouds to look at, no rain to listen to as it patters on the roof, etc., etc. This could lead to "seasonal-affective" depression-type situations for some of the astronauts, particularly if it's a chronic atmospheric problem.

Phobos: With a 6" scope would you be able to resolve the ice caps and continents against the blue ocean? I don't own a telescope yet so I couldn't even fathom an answer.

*I highly doubt it.

--Cindy

nirgal · 2002-07-23 15:05:48

But one thing does bother me a little bit: Have a look at the American flag on the lander in some of the "properly adjusted" pictures (properly adjusted, that is, according to NASA). The blue background behind the stars looks purple to me .... as though the red-gain is turned up too high!!

Fascinating!! Can you give me a link? :0 :0 :0

Phobos · 2002-07-23 19:20:59

Phobos, don't worry.
Mars will have spectacular night skies...
The zenith will always have stars to view, even during the day, so as for worrying about seing earth, it outta be the brightest object after your namesake, Phobos, and Deimos.
I've heard you'll even be able to make out the moon with the naked eye. although it just might be a whitish bump on the edge of the earth, assuming it is at the appropriate place in it's orbit.
Mars ought to have the finest skies known beyond Luna, with no atmosperic shiver like there is here...
Your friendly neighborhood Martian
-Matt

Wow, I hadn't thought about the possibility of seeing the moon from Mars. It makes sense though considering it's size. After all Mercury is similiar in size of the moon and it can be seen from Earth with the naked eye. I wonder if you'd also be able to see the four largest satellites of Jupiter. I've heard stories of people on Earth who can see them unaided, but I'm skeptical. Anyways, I think I have that photo of Viking on my computer, I'll go see and post it if I do have it.

Josh Cryer · 2002-07-24 16:11:04

The prospect of seeing the Earth and Luna from Mars is exciting. But I still think Phobos will be the most amazing thing to behold. I still can't picture an object the size of Manhattan passing through the sky three times a day... that's gotta send chills down your spine.

Shaun Barrett · 2002-08-03 22:09:14

Here's that flag:-

http://mars.jpl.nasa.gov/gallery/spacec … 00565.html

Phobos · 2002-08-03 22:54:06

Woah Shaun, I think your on to something with that NASA conspiracy theory of yours. Either someone got ambitious with the purple ink or we aren't being told the full truth! You know, I remember reading somewhere that the names of Iceland and Greenland were intentionally switched so people would flock to the big iceberg thinking it would be a green paradise and leave Iceland the province of a few people. Perhaps there are NASA officials sipping martinis on a Martian beach under a blue Martian sky berating us easily swindled sheep as we speak? Good work on sniffing out another dastardly NASA plot, that metal hat serves you well.

RobS · 2002-08-13 20:05:37

I was a graduate student working at the Jet Propulsion Lab on Viking's LIFT-SAG (Lander Imaging Flight Team Science Analysis Group) in July 1976 when Viking landed on Mars. I remember the first day's pictures were not color calibrated correctly and had a bluish sky. I remember an acquaintance of mine, who I think was involved in the color calibration, commenting on the problem. Viking landed in the middle of the night and the morning newspapers--those with color pictures, which were a lot fewer in those days--ran pictures of Mars with a bluish sky. But in Japan, morning came seven or so hours later, so Asahi Shimbun--a big newspaper--heard about the problem, and they had their photo editors run the picture through a reddish filter and printed the picture with the color of the sky corrected to pink. Then they sent a pile of the newspapers to JPL. I probably still have one at home somewhere, now yellowing and 26 years old. I suppose they sent the papers because they had corrected the problem.

Viking had an unusual camera system that, like television cameras, basically took three pictures, each in a different wavelength, which then had to be combined together to make a color picture. But the colors had to be calibrated. To perform the calibration, the Viking had a color test pattern imprinted on it; the color of each square was known. But calibration cannot be perfect, because (1) you look at the standard color pattern through a reddish atmosphere, and (2) dust settles on the test chart and changes the colors gradually. So the test pattern improved the calibration greatly, but never allowed it to be perfect. The first day they didn't have time to get it right.

-- RobS

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#1 2002-07-22 05:33:39

Re: Color of the sky on Mars - Pink, blue, or green even?

#2 2002-07-22 09:58:57

Re: Color of the sky on Mars - Pink, blue, or green even?

#3 2002-07-22 10:57:28

Re: Color of the sky on Mars - Pink, blue, or green even?

#4 2002-07-22 20:26:31

Re: Color of the sky on Mars - Pink, blue, or green even?

#5 2002-07-22 20:32:37

Re: Color of the sky on Mars - Pink, blue, or green even?

#6 2002-07-23 05:55:49

Re: Color of the sky on Mars - Pink, blue, or green even?

#7 2002-07-23 13:37:17

Re: Color of the sky on Mars - Pink, blue, or green even?

#8 2002-07-23 15:05:48

Re: Color of the sky on Mars - Pink, blue, or green even?

#9 2002-07-23 19:20:59

Re: Color of the sky on Mars - Pink, blue, or green even?

#10 2002-07-24 16:11:04

Re: Color of the sky on Mars - Pink, blue, or green even?

#11 2002-08-03 22:09:14

Re: Color of the sky on Mars - Pink, blue, or green even?

#12 2002-08-03 22:54:06

Re: Color of the sky on Mars - Pink, blue, or green even?

#13 2002-08-13 20:05:37

Re: Color of the sky on Mars - Pink, blue, or green even?

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