Perhaps, though I am to the understanding that C02 (reflecting what's mentioned a few posts ago) is a much more efficient scatterer of the blue component than, say, 02.<br /><br />In any event, Mars still won't have much of a blue component, due to the low atmospheric pressure (I'm not certain about the figures for scale height and optical depth for Mars - have to think about it) and suspended dust.<br /><br />A great example is that picture taken of a Martian sunset. The transmission path is at it's maximum, so the scatter will be at it's lowest, true. You'll note that there's a bluish area around the setting sun, but elsewhere is gray/red/brown.<br /><br />No doubt the scatter at high noon would be greater (least optical depth), but even then it's not a pure blue sky by any means. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis: </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>