How much dust is in Mars's atmosphere at ground level, and what's it made of?

I was thinking about the problems of fully automated robotic mining, and it occured to me that mining is a lot simpler if you don't have to move anywhere. For example, it's possible to mine the Martian atmsophere for carbon dioxide and water vapor just by pumping in the air and filtering out what you want.

Of course, there's the problem of dust, so you'll need to filter out the dust...

And that's when I had an "aha" moment. Why not mine the Martian atmosphere for dust? You could have a circular filter which constantly rotates past fixed "wiper blades". Accumulated dust falls from the wiper blades into a tube for processing.

Compared to a scooping robot, this mining robot doesn't need to move anywhere. It just sits and lets the dust come to it.

How much dust is available? Obviously, it will be different in a dust storm vs a calm day.

What is the dust made out of?

Thanks!

To answer my own question:

http://www.sciencemag.org/cgi/conten.../278/5344/1768

It seems that most Martian dust particles are magnetic, so they can be sifted out of the air with magnetic collectors. The particles are under 2 microns in size, with a density between 1 to 10 particles per cc.

Assuming 1 micron cubed per cc, the density is about 1E-12. So, let's assume a 1 square meter collection array with a fans sucking air through the grid at 30m/s. This translates to about a billion cubic meters of air per year. There's about a thousand cubic centimeters of dust per year in that air.

So, it seems like this is an interesting idea, but mining the Martian atmosphere for dust yields too little dust for it to be workable.

I was aware that the amount of Martian dust was pretty thin, but didn't have the specifics at my finger tips. Nice job looking it up.

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Hmm so sitting still doesn't work because the dust is too thin, but moving around doesn't work because the dust is too thick. I always thought dust would be what got a Mars expedition.

The problem with the rovers and dust is not how thick it is, but how opaque it is.

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There may yet be some hope for your idea. According to the arcticle, particles larger than 2 micrometers are rarely sufficiently magnetic to be held by the magnet. Even below two micrometers, up to 99% of the particles may be non magnetic. This still is a low yield, however dust storms occur a few days per Mars year; a fan would not be needed and the dust particles would be larger and more numerous, yielding perhaps a ton per year, with little or no fan energy required. Best of all passive sorting might yeild a high concentration of one or more useful kinds of dust. Neil

Sorry.. there go my off the cuff remarks again.... what I meant was in the context of the OP if the dust is too hard on moving machinery /parts .. yadda ..yadda..

What is maximum density ? And at what point will this start to create its own energy and create a star ?

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Thank God for magnetism.