03 December 2009

Occultation of Europa by Io

This Sunday the 6th of December, there is a very good reason for taking your telescopes out. Train your telescopes to the planet Jupiter at 8:30pm IST and you will notice that Io and Europa are very close to each other. Observe for couple of minutes more and you can notice that they are getting closer and closer. Yes, your guess is right, there will be an occultation of the Galilean moons Io and Europa. Io will occult Europa this evening, starting at 8:49pm IST. The event can be seen from all parts of India, the timings are for Bangalore co ordinates. Its better to start observing the moons from 8:45pm IST and time the event. The event will be for 5 minutes but better and accurate timing is a good exercise.

Io will be getting closer to Jupiter in its orbit and Europa is moving away from Jupiter.

Here are images that will help you in locating the planet Jupiter and one to help identifying the moons. Click in image for larger version.

Images generated from Cartes du ciel


  1. Are there any significances of these occultations? Are they helpful in any scientific studies?

  2. Occultations are a great way of ditermining the size, shape and compositions of objects. In this case also there are many areas that can benefit by observing and recording the event. Just to give an example, timing of these events are very important to improve the models of their orbits and investigating the effects of tides on the movements of Io and Europa.

    In 1991 scientists studied twelve occultations of Io, recorded them with a CCD camera during the mutual occultation. In events Io was covered by Europa, and these observations gave high quality astrometric information that was very useful in connection with infrared determinations of the locations of Io's volcanoes made by other investigators during the occultations.