RENEE MONTAGNE, HOST: Now, to something new from NASA. A few weeks ago, twin spacecrafts known as the Radiation Belt Storm Probes began orbiting the earth. And since then the probes have been sending back strangely beautiful recordings of the sounds of space. NPR's Jon Hamilton has more.</s>JON HAMILTON, BYLINE: This is one of the sounds. Scientists have known about it for decades. They call it the chorus.</s>JON HAMILTON, BYLINE: The chorus comes from the magnetosphere, an area where charged particles from the sun interact with the earth's magnetic field. Craig Kletzing from the University of Iowa says the interaction produces radio waves that just happen to be in the same frequency range as sounds we can hear.</s>CRAIG KLETZING: So you can do a direct translation from radio wave to sound wave and then you can listen.</s>JON HAMILTON, BYLINE: Kletzing says it appears that the chorus gets louder when the earth's radiation belts are growing stronger.</s>CRAIG KLETZING: We've known about this phenomena for a long, long time. I think people first were observing this back maybe even on the ground in the '50s. But the understanding of exactly how it's generated still remains one of the key scientific questions for this mission.</s>JON HAMILTON, BYLINE: NASA also hopes to get a better understanding of what's known as space weather, which can disable satellites and knock out power grids. The mission, managed by the Johns Hopkins Applied Physics Lab, is scheduled to run for the next two years.</s>JON HAMILTON, BYLINE: Jon Hamilton, NPR News.
Twin spacecraft recently began orbiting the earth, and the probes have been sending back strangely beautiful recordings of the sounds of space. Scientists call it the chorus. The sounds come from the magnetosphere, an area where charged particles from the sun interact with the earth's magnetic field.