[X] My Assistant

[Nirgal]

among the many new pancams at exploratorium there seem to be interesting
images showing what must be clouds, clearly defined as never seen before
at the Gusev site.

http://qt.exploratorium.edu/mars/spirit/pa...HEP2680L7M1.JPG

Interestingly, those are high-res pancam multi-filter sequences.

Questin for Dan (slinted) refering to our recent discussion about sky color:
would't this be wotrth a try to do interesting sky color composites.
Maybe you could use the brightest pixels
in the clouds as a white point reference ?

[Bill Harris]

Good discussion of the Martian sky, Ed.

Your observation of the Texas duststorm parallels my impression of the Earth skies due to volcanic dust/aerosols in 1982 from el Chichon and Pinatubo in 1991. I was able to also look at the sky in 1991 from an airliner at 35,000 feet, so I had a feel for the appearance of the dust at altitude. A dusky warmish color, increasing in density at the horizon, and a whitish halo around the Sun.

My own personal preference for viewing Mars is a bit less "butterscotch" so things don't look ochre, ochre, ochre, although it's not true color. I grew up in Birmingham, Alabama in the 60's, and our steel-mill polluted skies looked too much like that...

--Bill

[dvandorn]

Good discussion of the Martian sky, Ed.

Your observation of the Texas duststorm parallels my impression of the Earth skies due to volcanic dust/aerosols in 1982 from el Chichon and Pinatubo in 1991.  I was able to also look at the sky in 1991 from an airliner at 35,000 feet, so I had a feel for the appearance of the dust at altitude.  A dusky warmish color, increasing in density at the horizon, and a whitish halo around the Sun.

My own personal preference for viewing Mars is a bit less "butterscotch" so things don't look ochre, ochre, ochre, although it's not true color.  I grew up in Birmingham, Alabama in the 60's, and our steel-mill polluted skies looked too much like that...

--Bill

I have two things to say.

First, we need to remember that Mars is an entire planet, with complex landforms and weather patterns. While its atmosphere is far thinner than ours, it obviously changes in appearance over time and with regard to a number of different conditions, sometimes as frequently and dramatically as our own. So there really isn't such a thing as any one way the Martian sky appears -- its appearance changes during the course of the day, during the change of the seasons, and during changes in weather. Just like on Earth. (Now, as for me, I want to have a feeling not just for how the sky generally looks, I want a feeling for how it changes, and what conditions make it change in given ways... *smile*...)

Second, I think it's really, really fascinating how much most of us want to be able to visualize exactly what it would look and feel like to stand upon the surface of Mars. We want to know what the colors would be like, we want to know what the horizon would look like, and we especially want to know what the sky would look like.

I don't think there is any rational reason for a lot of us to feel so strongly as we do about this desire to *know* what it feels like to have Mars under our feet. (Or the Moon, or Titan... any and all places we can imagine ourselves.) But it's this desire that needs feeding, and it's this desire that drives and justifies the continuing exploration of space.

Rational or not.

IMHO.

-the other Doug

ps -- personally, from what I've seen, in my imagination I see Mars' sky as something that thins out so dramatically overhead and brightens up so dramatically along most of the horizon, with transitions from bright butterscotch to dark, dark violet, that it will give you a visceral sensation of how thin a skin of air surrounds you. If you've ever flown in an airliner at 35,000+ feet, you know how you can just sense the thick portion of the atmosphere, defined by how most of the clouds and haze float atop it? Well, on Mars, I think you'll be able to "feel" that layer as you stand at its bottom -- it will feel like a very shallow pool, indeed. DVD