|Image Credit: Transits Page; Text entered by AstronomicalEventsCalendar|
Callisto beautifully rests on top of the planet, as it's orbit appears to be above the planet, we must remember that these orbits are three dimensional - and that since Jupiter is titled towards us, it looks like Callisto orbits above. Sense Perception! Concerning the transit, you can see Io and Ganymede - Ganymede will swoop down and catch up to Io (they are not actually that far apart in the two-dimension scale, becasue of their orbits, but they appear to be far apart). The dual-transit itself will start at 17:46 UT and end at 18:22 UT, lasting only 36 minutes. If you can remember, this is very shorter than the October 24 transit.The next picture below concerns itself right before the transit - at 16:00 UT. Ganymede and Io are now very noticeable together.
|Image Credit: The Transits Page; Text entered by AstronomicalEventsCalendar|
If you're wondering what a Jovian dual-sahdow transit is? Look no further - Here, we can clarify the terms of dual-shadow transit, and dual-transit, becasue both can happen at the same time - the October 24 and 31 transits are great examples of these (among others). A dual-shadow transit occurs when two shadows of moons travel across the surface of Jupiter together (and yes this can also happen on any other planet with two or more moons, etc.), and then, when the two moons travel together, it is called a dual-transit. (The difference is just either the shadow or moon), but both have to cross Jupiter (or any other planet, etc.) at the same time. You can read more about Jovian transits in our last transit: October 24.
-all pictures below are credit The Transit's Page, Galilean Moons Simulator; text entered by myself-
Another object to note is the conjunction of Io and Ganymede again, but the next day:
2011-Nov-01 05:19 Conjunction of Io and Ganymede [144.0" W; 21.7" S].
TOTAL EVENTS FOR OCTOBER 31, 2011
2011-Oct-31 15:12 Conjunction of Io and Ganymede [44.7" E; 13.1" S]
2011-Oct-31 16:13 Transit Ingress of Io (All satellites no more visible to the east of Jupiter)
2011-Oct-31 16:18 Shadow Transit Ingress of Io
2011-Oct-31 17:18 Inferior conjunction of Io
(2011-Oct-31 17:45 Conjunction of Callisto and Europa [204.4" E; 38.1" S])*
2011-Oct-31 17:46 Transit Ingress of Ganymede (Double Transit Begin)
2011-Oct-31 18:10 Shadow Transit Ingress of Ganymede (Double Shadow Transit Begin)
2011-Oct-31 18:22 Transit Egress of Io (Double Transit End)
2011-Oct-31 18:26 Shadow Transit Egress of Io (Double Shadow Transit End)
2011-Oct-31 18:30 Inferior conjunction of Ganymede
2011-Oct-31 19:09 Transit Egress of Ganymede
2011-Oct-31 19:24 Shadow Transit Egress of Ganymede
*Object of Note!
(with thanks to the Galilean Moons Simulator)
Results of the October 31, 2011 Jovian Dual Transit
"After having such a prolific season of simultaneous Jovian dual-transits last May-June, it will be hard to accept the fact that we have only two more this 2011 season: October 24, 2011 and October 31, 2011. Each transits are an exact week apart (although times differ) and both are dual-shadow transits. Io and Ganymede both partake in each event, as their orbits must be aligned perfectly just for this week." Read more at the link above. (Basic insight of what happened).
31 October 18.23 UT
|Here's a simulation from WinJUPOS of what it will look like at 18:15|
Below is a picture computed (simulated) by Celestia software. You can see Ganymede and Io as the light blobs, and their shadows cast on the planet. If you would to see the picture clearer, you may click on it for higher resolution.
Although these are not the most high quality images available, they do beautifully illustrate the beauty of this transit. So, just to say - I will hopefully be receiving the 2012 Galilean moons calendar soon - so until next year....