CAPE CANAVERAL, Fla. (December 4, 2012)--Twin spacecraft captured the clearest radio waves yet from Earth's radiation belts and they sound like the chirping of birds.
NASA's Van Allen Probes have been exploring the hostile radiation belts surrounding Earth for just three months, but already, they've collected detailed measurements of high-energy particles and radio waves.
Scientists say these waves can provide an energy boost to radiation belt particles, somewhat like ocean waves can propel a surfer on Earth.
What's more, these so-called chorus waves operate in the same frequency as human hearing so they can be heard.
A University of Iowa physicist played a recording of these high-pitched radio waves at a conference Tuesday in San Francisco.
“People have known about chorus for decades,” he said.
“Radio receivers are used to pick it up, and it sounds a lot like birds chirping. It was often more easily picked up in the mornings, which along with the chirping sound is why it’s sometimes referred to as ‘dawn chorus.’”