Quote from: Xpleet on May 03, 2008, 09:19:50 PM

This image doesn't prove anything. It is taken from an article on a conspiracy theories website (redicecreations.com), and they have photoshopped it in a way that makes the red half look unnatural.
However, it quotes an article which at least makes an effort to explain why the image might be blue:
http://mars-news.de/color/blue.html - but when you look at the blue images you can clearly see that they've boosted the blue and green so much that the calibration swatch in the photo is too blue. Since they were claiming to use the calibration swatch to decide that the images should be blue, they've weakened their argument by overdoing it.
They don't give any worthwhile reasons why it should be blue - all can be easily discredited.
Quote

In this image the ice cap appears blue. Why? I think the image hasn't been calibrated correctly. The ice cap should be white, or even slightly tinted red by dust and dirt mixed in with the ice. If the image were calibrated correctly the clouds would also turn out much closer to white than blue. Viewed from the surface I believe these clouds would probably make the sky look white, but usually not blue.
Sunset photos on Mars have shown that blue light is scattered in a predominantly forward direction, so looking towards the sun the sky might look blue even when the sun is much higher in the sky. Looking away from the sun it is much less blue. Exactly how much less isn't obvious, but it will all depend on the sizes and the types of particles in the atmosphere. We should be able to rely on data from the designers of the cameras/filters to calibrate the raw data correctly, but what's frustrating is that these space agencies don't give us enough confidence that they've got it right. A space-proofed $100 camera with white balance disabled would do the trick ;P
Matt