2022-04-27, 08:50 PM
That's likely where I got the original method. The problem with Iapetus (which would make a great name for a paper, or maybe a movie) is that it has a weird orbit that probably has some pretty complicated perturbations. I'm looking into other solutions, but this rabbit hole just got a lot deeper, and I have other things I'm supposed to be working on right now. I may have to put it back the way it was and fix it another day.
By the way, eyeballing the Horizons data, it looks like the transit will occur between 2022-Apr-29 22:00 UT and 2022-Apr-29 23:00 UT. This is an unusual and difficult calculation to do accurately, so don't just assume the other source of information is actually correct about the date and time of the transit. JPL has to be able to navigate spacecraft near the moons, so they are the gold standard.
By the way, eyeballing the Horizons data, it looks like the transit will occur between 2022-Apr-29 22:00 UT and 2022-Apr-29 23:00 UT. This is an unusual and difficult calculation to do accurately, so don't just assume the other source of information is actually correct about the date and time of the transit. JPL has to be able to navigate spacecraft near the moons, so they are the gold standard.
Clear skies,
Greg
Head Dude at Skyhound
Greg
Head Dude at Skyhound