Jovian Extinction Event (JEE) Main Page
Modeling the Jovian dust field, moon atmospheres, Europa geysers, and Io’s Torus through JEE
Jovian Extinction Events (JEE) occur when an object experiences a loss of intensity as it passes behind dust or gas in the Jovian system. This loss of light or extinction can be caused by material gravitationally bound around one of Jupiter’s four major moons, material trapped in the magnetosphere or torus ring that surrounds Jupiter near Io’s orbit, or possibly Europa water geysers (paper pending). One can use an object passing behind a target of interest to probe the material around the object in front by measuring the change in light of the object behind as its light passes through the this material. Here is some good FAQ material:
The extinction phenomenon was first detected in 2009 during the end of the Jupiter Mutual Event (JME) season when Jupiter’s orbital plane was still edge on enough that the major moons were eclipsing and occulting each other (Degenhardt et. al, 2010). It was noted then that an anomalous photometric dimming began many minutes prior to Io occulting Europa or when Europa occulted Io, and an anomalous brightening was observed over many minutes post occultation.
The material surrounding Io migrates away and is captured for a period of time in Io’s Torus ring. When Io passes through the tips of the torus where the extinctive material is collimated to our line of sight that Io experiences a self extinction of its reflected light. During the IAEP2009 and JEE2010 Observing Campaigns it was established that Io suffers a sort of “self-extinction” while it transits its own orbit at the tips inside the Torus of Io. There is enough stray gas and particles to cause detectable magnitude loss with standard unfiltered observing equipment via extinction of the reflected sunlight from Io as it is diminished by the collimated line of sight Torus material at the most extreme eastern and western tips of the Torus. In 2010 John Talbot of New Zealand captured 5 hours of video during most of an Io transit of its western Torus tip. At that time in November of 2010 the orbit of Io was only 0.4 degrees inclined to our view from earth. This presented a large amount of Torus material collimated to our view which caused a very notable 0.13 unfiltered magnitude dimming during its transit through the western torus tip. The data from that run enabled us to derive a 5th order polynomial fit to Western Torus Tip transits of Io and has enabled us to create reliable predictions of future Io Torus JEE. The Torus does have a wobble relative to Io’s orbit, so Io is sometimes in the Torus material and sometimes out. The following discussion explains this better: http://scottysmightymini.com/JEE/IoTorusJEE_Discussion2014-Mar-08.pdf
2009 JEE events were detected around JME occultations where the body of the target moon in front passed directly in front of the probing moon in back. From early 2010 to late 2014 there were no JME occultations involved. Instead conjunctions (near occultation) occurred where the target moon passed in front of the probing moon from our line of sight and the probing moon was separated by up to 10 arc seconds. Thus the moon in back was probing regions above or below the poles of the target moon. Predictions of dimming were initially based on a first order assumption of a spherical distribution of material around a target using trends observed in 2009 at the equators. The IAEP2009 and JEE2010-JEE2013 Observing Campaigns yielded new anomalies. We have a paper pending on this anomaly likely linked to water geysers on Europa. We hope to document more of these anomalies and will eventually have an entire new predictions and results section just for Europa water geysers once additional observations validate this theory.