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This answer links to the 2008 Phys.org article with the catchy title NASA's dirty secret: Moon dust.

The article says:

Luckily, lunar dust is also susceptible to magnets. Tiny specks of metallic iron (Fe0) are embedded in each dust particle's glassy shell. Taylor has designed a magnetic filter to pull dust from the air, as well as a "dust sucker" that uses magnets in place of a vacuum. He has also discovered that microwaves melt lunar soil in less time than it takes to boil a cup of tea. He envisions a vehicle that could microwave lunar surfaces into roads and landing pads as it drives, and a device to melt soil over lunar modules to provide insulation against space radiation. The heating process can also produce oxygen for breathing.

In other words, the article is not reporting on a peer-reviewed article, but instead just mentioning a claim by somebody, without evidence, except for the sketch below.

Is this really true? Can you really melt lunar regolith with microwaves in a remotely practical way?

Or are they really just talking about some permutation of a conventional RF inductive heating of a coil, which is wrapped around a conventional crucible?

Professor Taylor is a well recognized geochemist and worked with the Apollo astronauts and scientists.

On the other hand, as a calibration point, the article also says:

NASA will use these findings to plan a safer manned mission to the Moon in 2018.

Lunar dust melts readily when exposed to microwave energy says Professor Larry Taylor

Lunar dust melts readily when exposed to microwave energy. Professor Larry Taylor of the University of Tennessee envisions a lunar paver fitted with microwave generators that could sinter, or melt, lunar soils into landing strips or roads. Credit: Larry Taylor

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    $\begingroup$ Of course a lot of microwave power is neccessary to use the lunar paver at an acceptable speed expressed in meters per second instead of meters per hour or day. Cooling of the microwaves antennas might be needed. $\endgroup$ – Uwe Feb 22 at 16:34
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Yes, really, and there's a NASA study that describes this method.

The microwaves couple strongly with the Fe0 to such a degree that a sample of Apollo soil placed in an ordinary 2.45 MHz kitchen microwave will literally begin to melt before your tea-water boils.

It's also been published (see note 31 of the above document), and it's been tested (by Taylor) on lunar samples:

The unique properties of lunar regolith make for the extreme coupling of the soil to microwave radiation. Space weathering of lunar regolith has produced myriads of nanophase-sized Fe0 grains set within silicate glass, especially on the surfaces of grains, but also within the abundant agglutinitic glass of the soil. It is possible to melt lunar soil (i.e., 1200-1500 0C) in minutes in a normal kitchen-type 2.45 GHz microwave, almost as fast as your tea-water is heated. No lunar simulants exist to study these microwave effects; in fact, previous studies of the effects of microwave radiation on lunar simulants, MLS-1 and JSC-1, have been misleading. Using real Apollo 17 soil has demonstrated the uniqueness of the interaction of microwave radiation with the soil.

'The Lunar Dust Problem: From Liability to Asset' is a conference paper. The material has also been published in the Journal of Aerospace Engineering, which is peer reviewed.

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  • $\begingroup$ "will literally begin to melt before your tea-water boils" and "almost as fast as your tea-water is heated" Does the regolith melt before or after the water boils? $\endgroup$ – Uwe Apr 5 '19 at 14:03
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    $\begingroup$ @uwe I think that is Fe0 rather than FeO. That is metallic iron (Oxidation state 0) rather then iron oxide $\endgroup$ – Steve Linton Apr 5 '19 at 15:56
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    $\begingroup$ Small particles of iron embedded in. Glassy material is how I read it. So not conductive in bulk $\endgroup$ – Steve Linton Apr 5 '19 at 16:39
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    $\begingroup$ Proton from solar wind reduces FeO to generate Fe, the paper says. Will that give liquid water trapped in soil? $\endgroup$ – Prakhar Apr 5 '19 at 16:58
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    $\begingroup$ Yes, that should be Fe zero $\endgroup$ – Hobbes Apr 5 '19 at 17:06

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