http://mashable.com/2012/10/01/earth-song-nasa/
Need some soothing sounds to put your Monday blues in perspective?
We've got you covered. Grab your headphones and check out this hot new
MP3 track from NASA, currently the number one hit across the universe:
That's the sound of the Earth "singing," as recorded by the
awesomely-named Storm Probe mission — a couple of satellites
investigating the famous Van Allen belts, intense radiation zones that
surround our planet like a doughnut. The Storm Probes, launched last
month, are mapping the density of charged particles.
The whale song is an audio rendering of radio waves captured by the
Probes and caused by the two Van Allen belts, inner and outer. You don't
actually hear the audio in space, of course, but the radio waves —
known as "chorus" — are for real.
Ham radio operators have been hearing chorus in the background for
years, but there's never been a recording this clear. "Our data is
sampled at 16 bits, the same as a CD, which has not been done before in
the radiation belts," says mission scientist Dave Sibeck. "This makes
the data very high quality and shows that our instrument is very, very
healthy.”
The instruments may be, but chorus isn't. The soothing radio waves
are used by loose electrons to gain energy, much like a surfer gaining
speed on real waves — creating what NASA calls "killer electrons" that
can harm humans and electronics.
Sibek's next goal: use the two spacecraft in tandem to create a
stereo recording of chorus. That should make for a truly killer sound.