(Point being from earth it looks red. Why are so many of you convinced it's got a blue atmosphere and they're hiding it from us?!)
This ridicule is ignorance that needs to be denied.
Your derision is misplaced... though rather common among pseudo-intellectuals with only enough knowledge to be dangerous, without actually being truly
informed. Why believe that it would be reasonable to see a blue sky on Mars?
Simple science, really. Most planets with an atmosphere will tend to have a blue sky due to Rayleigh scattering. The color of the sky is largely a
function of scattered light. The sky might appear DARKER due to a less-dense atmosphere, but would not change from blue to red.
Sure, in the middle of a sandstorm or immediately after, it might be discolored... but the sandstorms are not constant, and the air does clear at
least somewhat, giving decent visibility across substantial distances.
There are also substantial problem with assuming that a major fraction of the blue/green wavelengths would be absorbed by "constant" dust in the
atmosphere... one, the solar cells would stop providing nearly the power levels that they need to provide, since their primary response range is from
blue light, not red.
Two, enough dust to absorb that high of a fraction of the blue and green wavelengths would make the entire surface substantially darker, and since a
majority of the light at the surface would necessarily have to be scattered light, we wouldn't see shadows that were nearly so sharp as we do.
As I recall, Viking only noted two or three significant dust storms over a three-year span. Yes, they happen, but it's not like it's wall-to-wall
dust storms 24x7.
We also see from orbital photographs that the sky is quite often very clear... the surface is not habitually hidden due to some wall-to-wall murky
haze. A predominant number of orbital pictures are remarkably crisp, indicating that the intervening atmosphere is (relatively) clear. A majority of
the obscuration of surface pictures seems to come from water-ice clouds.
NASA's own folks (and many other respected science outlets) have said for some time that they would not be at all surprised to find a blue sky on
Mars... why then are you expressing mock amusement towards those who agree with them? The supposition of a blue sky typically appearing on Mars is
Here are a couple of quick references. You could have found them yourself if you had bothered to Google the subject and invest a couple of minutes in
actual learning... a pity that a smirk and a dismissal is so much easier to throw out there.
From the John Baez Physics FAQ
"The colour of the Mars sky will change according to weather conditions. It should be blue when there have been no recent storms, but it will be
darker than the earth's daytime sky because of Mars' thinner atmosphere."
From a Hubble Telescope press release
just before the landing of
Pathfinder (if you read the article, you'll notice that Jim Bell from Cornell was involved here... the same fellow in charge of the color balancing
for the Rovers):
"If dust diffuses to the landing site, the sky could turn out to be pink like that seen by Viking," says Philip James of the University of Toledo.
"Otherwise, Pathfinder will likely show blue sky with bright clouds."
There is a well-researched paper
by Ron and Gilbert Levin which examines the
color calibration issue. It is excellent reading for those interested in actually educating themselves on the subject, instead of just flinging
mockery. It does a good job of poking holes in the "conventional wisdom" explanation about suspended dust vs. Rayleigh scattering.
[Edited on 1-30-2004 by BarryKearns]