I scuba dive, and I’ve noticed that when the current is brisk through some coral formations, small swirls behave exactly as dust devils. Would the researchers predict that any magnetic phenomena could be produced by silt in salt water?

Lindsey Randal Potts
San Antonio, Texas

Probably not, says William M. Farrell of NASA. Any charges that might build up on the particles of silt would be pulled away almost immediately by the water molecules surrounding them .–S. Perkins