[The following is an exact transcript of this podcast.]

On Earth, snow crystals, as we all know, form from frozen water. But scientists believe there are also flakes that fall on Mercury—and they’re made of iron. They published their findings in the journal Geophysical Research Letters. Investigators have been trying to figure out why Mercury is the only other terrestrial planet in our solar system that has a global magnetic field. It's about one hundred times weaker than earth's. No previous models have been able to predict what would cause this type of situation. So researchers at the University of Illinois and Case Western University set up an experiment to try to figure it out.