The Van Allen Belts are donut-shaped rings of radioactive particles that encircle the Earth. They can damage satellites and pose a bit of a risk for human astronauts who venture outside our planet's protective magnetic field and into the regions of the belts. Back in high school, you probably learned that there were two of them. But, it turns out, under certain situations, this planet actually has three Van Allen Belts. The story about this at Nature News, written by , is a joy to read. You really get a sense of how totally scientists' minds were blown by this discovery.