Nipping it in the bud - Mars photos are NOT altered

[TrogL]

(fixed title)

There's a new conspiracy theory started up saying that NASA, for some nefarious reason, is altering the photos coming in from the Mars lander.

They are not. Here is the explanation.

http://www.atsnn.com/marscolors.html (may be overloaded)

In one sentence, it has to do with how the digital camera perceives infrared light.

I have related experience. Once upon a time I was doing some photography using really early 400 speed colour film. I shot a picture in the kitchen that happened to include a pot cooking on the stove. When the pictures came out, it looked like the element was hot enough to smelt aluminum. It wasn't. What had happened was the film was really sensitive to infrared radiation and was reporting it as "red".

[StClone]

1. Still under the misapprehension, aaaiii

That we have been on the Moon and landed probes on Mars I see. I'll nip this in the bud one better.

[Ediacara]

3. LOL :-)

[PVnRT]

2. So they aren't "colorizing" them, then?

That's the only thing that I have heard about altering the photos

[Heyo]

4. They do this...

They have one sample of a particular color.. keep one sample here and send one along with the rover..

Then when they take a picture of the color sample (I think it's a little stick on the rover that they can point the PanCam at, not sure exactly how they go about it), they adjust the hue and brightness and contrast to make the picture of the color sample match the KNOWN color.. this way they can be more sure that the pictures they have look exactly like it would look with your own 2 eyes..

It's just a way of calibatring the pictures sp they look right...

Heyo

[Ediacara]

5. I had read some conspiracy theories concerning color calibration

on Pathfinder. The theory goes that the camera has a color pallette printed on the lander and that the NASA engineers would use that to calibrate the colors on incoming photos. Well, so says the theory, it's just not right because in photos with the American flag (which is printed on the lander and rover also), the flag looks orange and purple, instead of red and blue.

This all goes to "prove" that when you recalibrate the color on the photos so that the flag's colors are correct, then the Martian atmosphere is a hazy powder blue (like the Earth's) instead of the milky pink that everyone else thinks.

Although their photos are convincing, I don't buy it. Mars' atmosphere should be full of silt-sized grains of hematite (there is hematite dust on the ground everywhere on Mars, and extremely violent storms are well known). The sky should be hazy and pinkish, much in the same way smog turns the sky brownish.

EDIT: for clarification of a sentance.

[uncle ray]

6. thats real simple

the flag, correctly color corrected, would appear orange and purple on mars, in the red atmosphere or whatever. it it was red white and blue in the pics, it would likely be OVER corrected.

[Ediacara]

8. Oh I agree

Like I said, I think that a blue sky on Mars is not correct. I was just explaining one of the conspiracy theories about color correction of Martian photos.

Your explanation (white light going through a pink atmosphere making the flag look orange and purple) is not something I had even thought of, but probably correct :-)

[Cannikin]

13. here ya go...

Reply to post #4

[TrogL]

7. Here's the discussion on slashdot

http://slashdot.org/article.pl?sid=04/01/19/1258202&mode=thread&tid=134&tid=160

[TrogL]

9. Apparently the original article is offline

Here's a NASA link about the camera.

http://marsrovers.jpl.nasa.gov/mission/spacecraft_instru_pancam.html

[PsychoDad]

10. Rayleigh scattering on mars...

Is the same as on earth. The only thing about the martian atmosphere that may cause it to look pink or red is the presence of martian dust. Dust which would not always be present.

[Ediacara]

12. The dust (hematite) might always be there

The dust is aparently pretty fine grained and is kicked up by violent storms fairly often. There may not be enough time between storms to remove the dust from suspension, and so it might always be there.

On Earth, smog just doesn't settle out, and ash from volcanoes can stay in the upper atmosphere for decades, only settling out after decades.

[rman]

14. also Mars atmosphere is much less dense then on Earth

(1/100th earth amospheric pressure) so there probably just isn't enough of it to have it appear to be blue, as it is on earth.
It's different when light from the sun takes a longer path through Mars atmosphere, ie at sunset and sunrize.

As shown in the Pathfinder images:
http://nssdc.gsfc.nasa.gov/planetary/marspath_images.html

[TNDemo]

11. I've never nipped a bug.

I always nip a bud.

[Buns_of_Fire]

15. In that case, we have a problem, Houston...

IN WAKE OF NASA PHOTOS,BUSH ORDERS INVASION OF MARS