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The situation: the good guys are attempting to infiltrate an enemy base, and cause mayhem either in person and/or by planting explosives and running away. They know there is a big dust storm on the way so they can time their infiltration for before, during, or after the storm. (This is for a roleplaying game plot I want to run – I’d like to give the players the option of planning when they want to arrive).

The context: the planet they are on is in the grip of a massive ice age, so dust storms are very much a thing. Summer arrives, glacial out-wash plains dry out, the wind picks up rock which has been ground into a fine powder by glaciers and hey presto – a dust storm.

The tech-level: assume it is a slightly shinier and more efficient version of now. No super-science or psionic powers.

The question: So what will all this dust do to the capabilities of any infrared imaging devices set up around the base to spot folks sneaking in? (You can assume the cameras are properly sealed to prevent dust getting inside them). I’ve read that firefighters use thermal imaging kit in smoke-filled buildings. Would such a thing work as well for outdoor cameras in a dust storm?

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  • $\begingroup$ Typically you'd choose one of [science-based] and [hard-science] to apply to your question. This one uses both, which makes it somewhat unclear what requirements you intend to place on answerers. I'm adding the hard-science notice, but consider choosing just one of those two tags and if you go with [science-based], flag this for moderator attention so the hard-science notice can be removed. $\endgroup$ – user Sep 17 '17 at 15:14
  • $\begingroup$ @MichaelKjörling. Thanks - I've removed the science-based tag. $\endgroup$ – DrBob Sep 17 '17 at 15:23
  • $\begingroup$ I can't really add this as an answer, but you might be interested in this Mythbusters episode (S6, Ep192, Dust Devil). Kari, Grant and Tory try to pull off a kidnapping using various methods in ways that thermal imaging cannot (hopefully) detect. The base of the myth begins with dust clouds. It's been a while since I have watched it, so I can't give too much detail here. $\endgroup$ – PlanetAlexanderProjects Sep 18 '17 at 7:17
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In general dust will scatter radiation that is smaller than the average dust size. Thermal radiation being longer wavelength than light will be scattered less.

Peak wavelength for something at 400K (bit over boiling point of water) is about 7 microns. This is still pretty fine stuff, so dust would do a pretty good job of blocking it.

By 1000 K (727 c) wavelength has decreased to 3 microns.

For comparison red light is about .7 microns.

Caveats:

There is a lot less in the way of thermal sources than visible sources, once you get a few hundred degrees above ambient.. Good enough amplifiers will give you at least a vague glow.

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I found an interesting article on the NASA website that may be relevant. Apparently the dust in Martian storms is electrically charged, so it will stick to solar panels and cover them. They may also stick to and blind cameras during a dust-storm. As for if the airborne dust would block infrared, it has to deal with the size of dust particles, density of dust, and the temperature of the dust. (If the dust is hot enough it may emit more infrared.

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