Magnetic Moondust

Researchers have discovered something odd about fine-powdered moondust - it's magnetic.

Photo courtesy of Larry Taylor In Taylor's lab, moondust scattered onto a wire mesh lines up with a magnet inserted below.

Thirty-plus years ago on the moon, Apollo astronauts made an important discovery: moondust can be a major nuisance. The fine powdery grit was everywhere and had a curious way of getting into things. Moondust plugged bolt holes, fouled tools, coated astronauts' visors and abraded their gloves. Very often while working on the surface, they had to stop what they were doing to clean their cameras and equipment using large--and mostly ineffective--brushes.

Dealing with "the dust problem" is going to be a priority for the next generation of NASA explorers. But how? Professor Larry Taylor, director of the Planetary Geosciences Institute at the University of Tennessee, believes he has an answer: "Magnets."

The idea came to him in the year 2000. Taylor was in his lab studying a moondust sample from the Apollo 17 mission and, curious to see what would happen, he ran a magnet through the dust. To his surprise, "all of the little grains jumped up and stuck to the magnet."

"I didn't appreciate what I had discovered," recalls Taylor, "until I was explaining it to Apollo 17 astronaut Jack Schmitt one day in my office, and he said, 'Gads, just think what we could have done with a brush with a magnet attached!'"

Photo courtesy of Keller et al, 1999 A microscopic image of the iron-specked glass that coats moondust.

"Only the finest grains (< 20 microns) respond completely to the magnet," notes Taylor, but that's okay because the finest dust was often the most troublesome. Fine grains were more likely to penetrate seals at the joints of spacesuits and around the lids of "pristine" sample containers. And when astronauts tramped into the Lunar Module wearing their dusty boots, the finest grains billowed into the air where they could be inhaled. This gave at least one astronaut (Schmitt) a case of "moondust hay fever."