Bizarre Features of Saturn’s Radio Emissions
|Play audio (shift-click to download) (13 seconds)|
|A Java animation is available which features a moving cursor synchronized with the audio. This works best with the Java 1.4.2 or newer plugin for your browser which is available from Sun. (Install the “JRE” for your platform.)|
|Saturn is a source of intense radio emissions. 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. The Cassinispacecraft began detecting these radio emissions in April 2002 when Cassini was 2.5 astronomical units from the planet using the Cassini Radio and Plasma Wave Science (RPWS) instrument. The RPWS has now provided the first high resolution observations of these emissions that show an amazing array of variations in frequency and time. In this example, it appears as though the three rising tones are launched from the more slowly varying narrowband emission near the bottom of this display. If this is the case, it represents a very complicated interaction between waves in Saturn’s radio source region, but one which has also been observed at Earth!
The sound of the radio emissions can be heard by clicking on the button labeled “Audio” or in an animated version (which shows a cursor that indicates time on the spectrogram) by clicking on “A Java animation.” Time on this recording has been compressed such that 13 seconds corresponds to 27 seconds, or, about 2x real time. Since the frequencies of these emissions are well above the audio frequency range, we have shifted them downward by a factor of 260.Bill Kurth
RPWS Deputy Principal Investigator