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Jupiter Emissions

Click on Links below for charts and sound recording files

Jupiter Io-A and Io-C: 17 April 2009 Jupiter Io-B: 18 April, 2009 Jupiter Io-B: 5 September, 2009
Jupiter Io-B: 14 April, 2010 Jupiter Io-B: 16 May, 2010  
Jupiter/Io-B: 7 August, 2011 Jupiter/Io-B: 14 August 2011 Jupiter/Io-A: 18 August 2011
Jupiter/Io-B: 24 October 2011 Jupiter/Io-C and N: 30 October 2011 Jupiter/Io-B: 31 October 2011
Jupiter/Io-B: 5 November 2011 Jupiter/Io-B: 7 November 2011 Jupiter/Io-B: 2 December 2011
Jupiter/Io-B: 7December 2011 Jupiter/Io-B: 9 December 2011 Jupiter/Io-B: 14 December 2011
Jupiter/Io-B: 09/10 January 2012 Jupiter/Io-B, 19 October 2012  

Note:  All times and dates are UTC. All Reeve Observatory charts and sound files were recorded from Radio SkyPipe II.  The sound files were processed using GoldWave if needed (for example, to eliminate one channel from a stereo recording).  It is best to listen to the sound files while in a very quiet room or with high-quality headphones. Avoid using laptop speakers.

Brief Explanation of Jupiter Radio Emissions

Noise bursts from Jupiter are classified as L-bursts and S-bursts: 

  • L-bursts sound like ocean surf on a beach and can have a swishing sound 
  • S-Bursts sound like pebbles thrown on a tin roof or the snapping and popping sound of cooking popcorn. Each S-burst lasts for a few thousandths of a second.  S-bursts occur at rates as high as several dozen per second

Investigators have determined that probabilities of detecting Jupiter emissions strongly depend on the following factors (see definitions below table):

  • Jovian Central Meridian Longitude (CML)

  • Io Phase

  • Jovicentric declination of the Earth (De)

The combinations of CML and Io phase values that have increased probabilities are called Sources. The sources are named Io-A, Io-B, and Io-C for the Io-controlled (or Io-enhanced) emissions and A, B, and C for the Non-Io-controlled emissions. Emissions are more likely to be received for higher (more positive) De. De varies from about -3.4 to +3.4 degrees over an 11 year cycle due to the changing Earth and Jupiter geometry as they orbit the Sun at different rates. A positive peak occurred in October 2011 and the next negative peak will be in 2018.



Io Phase





200 - 290

195 - 265


Mostly L-bursts


90 - 200

75 - 105


Mostly S-bursts


290 - 10

225 - 250


L- and S-bursts



200 - 290


RH or LH circular or elliptical



90 - 200


290 - 10


CML        The System III longitude of Jupiter facing the Earth at a certain time

Io Phase   The orbital position of Io with respect to Jupiter and Earth. The Io phase is 0 degrees when Io is directly behind Jupiter as seen from Earth. The Io phase increases as Io orbits until it becomes 180 degrees when Io crosses in front of Jupiter as seen from Earth

De             The declination (angular distance north or south of the celestial equator) of the Earth as seen from Jupiter

The above information was adapted from the following sources:

Jupiter's moon Io (below, courtesy NASA).