Who says in space no one can hear you scream? Sonic material is among the many data that the spacecraft Cassini is collecting on its mission. NASA has posted a fascinating WAV file of emissions from the planet Saturn that fall in the radio spectrum (WAV).
The recording is spooky as heck, just waves of what seem like otherworldly moans — well, they sort of are otherworldly moans — that could easily have served as sound cues in an episode of Star Trek, UFO or Space: 1999. As one friend said, it could just as easily have been part of the score to Forbidden Planet, by Louis and Bebe Barron; how is it that their nascent electronic work sounds so much like the real thing?
The NASA online coverage of Cassini explains the science behind the sounds, and how they’ve been prepared for human ears:
Saturn is a source of intense radio emissions, which have been monitored by the Cassini spacecraft. The radio waves are closely related to the auroras near the poles of the planet. These auroras are similar to Earth’s northern and southern lights. This is an audio file of radio emissions from Saturn. The Cassini spacecraft began detecting these radio emissions in April 2002, when Cassini was 374 million kilometers (234 million miles) from the planet, using the Cassini radio and plasma wave science instrument. The radio and plasma wave instrument has now provided the first high resolution observations of these emissions, showing an amazing array of variations in frequency and time. The complex radio spectrum with rising and falling tones, is very similar to Earth’s auroral radio emissions. These structures indicate that there are numerous small radio sources moving along magnetic field lines threading the auroral region. Time on this recording has been compressed, so that 73 seconds corresponds to 27 minutes. Since the frequencies of these emissions are well above the audio frequency range, we have shifted them downward by a factor of 44.
That compression is similar to the effects implemented on the recording of an iceberg that I wrote about back in May (disquiet.com). That iceberg story has been one of the most popular posts on Disquiet.com this year. More info on Cassini and Saturn at nasa.gov, where the three images above were made available. For additional reading and listening, I mentioned an NPR story on Cassini’s recording in August 2005 (disquiet.com, npr.org) and also European Space Agency posts of Cassini recordings from Titan, one of Saturn’s moons, in January that year (disquiet.com, esa.int). (Thanks to Scott A. Gilbert, of apeshot.com, for the outer-space tip.)