By now, most of us know what the Earth looks like from space. But what it sounds like is another matter. Scientists have long known that radiation belts surrounding our planet—also called the Van Allen belts—produce a storm of electromagnetic waves across a range of frequencies. When reproduced as sound instead of radiation, the result is a string of chirps, chatters, whoops, and whistles reminiscent of an extraterrestrial jungle from a sci-fi movie. Yet despite their otherworldly tenor, they are perhaps the most earthly of sounds.