[alnitak]

Because it's a mono CCD camera, with various filters that can be used in front of it. If you just want to have a look-see mono is faster to shoot and takes less bandwidth to transmit to earth. I presume the science guys would rather have more B&W pictures than 3 times fewer colour ones (A colour pic requires you to take 3 separate exposures). Besides we know the colour - it's red :-)

That said, I hope Opportunity takes some colour photos of that rock outcrop.

There is no such thing as a colour CCD sensor. They are all basically just electronic photon counters, even the "colour" ones in eg. consumer digital cameras actually have an RGB colour filter matrix laid over the top of the pixels.

[lonevoice]

Thank you so much! Great explanation and I think I actually understood it.

[Don Joe]

There is no such thing as a colour CCD sensor.

Actually, there is. Foveon makes it, and currently Sigma is the only vendor using it.

Foveon X3 technology.

They are all basically just electronic photon counters, even the "colour" ones in eg. consumer digital cameras actually have an RGB colour filter matrix laid over the top of the pixels.

Foveon's X3 does not use a filter matrix. It is a true color image sensor.

Apart from Foveon, there are also the "traditional" color camera designs, which use three (or four) sensors, with beam splitters, based on the same concept as the legacy NTSC cameras (RGB and Luminance). There are alignment (and backfocus) issues, but properly set up, with a retrofocus lens suitable for use with them, the provide color images, rather than a filtered matrix.

[null and void]

There is no such thing as a colour CCD sensor. They are all basically just electronic photon counters, even the "colour" ones in eg. consumer digital cameras actually have an RGB colour filter matrix laid over the top of the pixels.

Carver Mead's Foveon chip is an actual color image sensor. He does it by stacking sensors with different peak wavelength sensitivities.

But then again he's always been a clever fellow, he and Lynn Conway changed the basic rules of IC design - design the chip to the baseline process, rather than tweak the process for every new design - and THAT played a large part in the IC revolution.