This undated image made available by NASA and the Goddard Space Flight Center shows an artist's rendition of the Van Allen Probes in orbit around Earth. The twin spacecraft have captured the clearest sounds yet from Earth's radiation belts - and they mimic 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 measurements of high-energy particles and radio waves in unprecedented detail. Scientists said Tuesday, Dec. 4, 2012 these waves can provide an energy boost to radiation belt particles, somewhat like ocean waves can propel a surfer on Earth. (AP Photo/NASA/Goddard Space Flight Center)
Read the article: Cosmic radio waves mimic chirping of 'alien birds'