Good to know! I've never liked MMDDYYYY, but it's funny they had to reverse the order to get around the conflict - kind of surprised the US didn't argue for YYYYDDMM, though. As you note, I mainly like it as it allows easy chronological ordering by date.
As for mutual occultations, Saturn's plane will be edge-on in March 2025, but it will appear close to the Sun then. Otherwise, it's close to edge on again in late October/early November. Thanks for the link to that site - I didn't know there was an easy way to list Saturnian moon events. Looks like there will be a few involving Tethys, Dione and Rhea that would be worth looking at.
You're more than welcome.
Now, some anoraky bits, as I could be bothered to do a bit of a more in depth websearch today:-
It turns out YYYY-MM-DD is IS0 8601 so may well have first been standardised for the business community, however it would not surprise me if archival astronomy data had been using it for decades before. Then again Julian Date would normally be used, however some things (eg variable stars) can use both at times as redundancy check, and I've seen both logged in fuller scientific FITS image headers.
Observatory code 500 is indeed geocentric, so should list all instances for all times and events.
I tried it with code 000, Greenwhich, which is near enough for me, and it gave far less results, pretty much all of which were unnice or pointless or really really difficult (eg shadow 1 on 2, and just seeing 2 can be hard enough for a lot of folk with normal sites and non-behemoth telescopes, imaging wise I know not). From cursory glance it looks like it takes nighttime and altitude into account for the location chosen, so picking a site and also taking the 500 list should help those most interested !!! The full explanation of their 'multisat' code is in French it seems with no easy found English translation. !!!
I tried one of the generic input options on that site but I was really, really guessing the date range and even if I extended the timeout limit I still got timeouts.
I could not find any Saturnian Satellite transit or eclipse transits there, one option seemed to give satellite eclipses, but due to timeout I couldn't check. The English page was well translated but the use of terminology was possible ambiguous (eg satellite eclipses, is that eclipses or eclipse transits or both?). Some pages are only in French so I may have missed a service which someone using a web translator might find.
Looking around their webpages it seems they have a campaign whenever the Galilean Satellites are mutualising, there were webpages for past events all called PHEMUyy (yy = 03, 09, 15, 21). So this may be an interesting place to look come PHEMU27/8.
GENERAL SIDEWAYS IMCCE STUFF :- those of us of an ancient disposition remember times when there were few microcomputers, if any, least of all any that could run obscure astronomy code (usually written in fortran in those days and needing compiling locally with no microcomputers likely having fortran available, at least cost wise).
If you are one of those you may remember going to the reference section of the nearest big library and sitting there jotting down stuff from the Astronomical Almanac, in those days published in alternate years by USNO and HMSO. Now, during the privatisation fad of those days HMSO was more or less got rid of because it cost money and certainly no longer published the Astronomical Almanac so I believe it has been a USNO publication for quite a time now.
The contents were computed by, and still are, and provided by, USNO in USA and Her/His Majesty's Nautical Almanac Office in the UK (probably at Greenwhich Obseravtory if you go back into true history, dunno nowadays). The two nations' reasoning behind this was of course the derived Nautical Almanac, which in the early days of hand computing each did a local version of independently.
There were a couple of independent National organisations still existing though, the history of which I'm not as clear on. One was the Paris Observatory which did Solar System celestial mechanics stuff going way back and still seems to make contributions to the Astronomical Almanac. IMCCE seems to be the current incarnation of that. Here's a generic ephemeris generator :-
https://ssp.imcce.fr/forms
The other traditional included in the Astronomical Almanac was I believe Pulkova, eventually being generated by the then Soviet Union, now done by the SAI in Russia. These were usually asteroid data. Which may explain this page http://nsdb.imcce.fr/obspos/index.html . In the early days of Russian scientific revolution one of the Tsars (Peter?) imported a lot of scientists from places like France and German nation states in order to kick start science in Russia, and of course Astronomy as a practice in those days concentrated very much on naval requirements and he was also building their first big navy. Traditional astronomical cooperation harking back that far appears to have held ever since, via Soviet to near current times (until possibly recent events).
I witter on at length on this stuff because they all would have had a direct remit from the IAU once established to be in charge of certain aspects. There would also have been ones Germany was formerly involved in due to historical reasons but just about all of these seem to have been lost to other nations after WWI, even before the IAU was formed, or possibly connected given the proximity of dates.
The point being that until NASA celestial mechanics had become somewhat dead as a subject in places like the USA losing out to astrophysics and cosmology, whereas in non-Anglophone nations these objects still had a strong observational tradition. And that's why some of this stuff is hard to find. Granted JPL does a lot of Solar System stuff nowadays but tends to be primarily a big orbit database, whilst Minor Planet Center is geared to asteroids and comets.
All above is from memory of stuff learnt bit by bit over long times from reading stuff in books I likely no even longer possess (or may have never personally owned or even been allowed to remove from libraries having to take notes in situ in pre-internet days) so exactitude may be challenged at times.
Remember, look around, using non-google based and similar websearches will also assist in finding obscure but still available stuff, and be patient enough to dig as far as three or four pages (probably would have to dig twenty pages in google style based stuff with advertisement pushed, frequency of hits over relevance biased, often location anchored (always use global) services).
Edited by yuzameh, 07 April 2024 - 11:30 AM.
