Perhaps I have missed it, but I have checked the three campaign settings, and cannot find how long a single orbit of the moons is. It takes 77 years for them to converge, and while I could probably work out RxGy=37577, I was hoping someone had answered that question.
Ok, someone did some space nerdery about lunar orbits:
Their basic approach is
“There is a major conjunction every 11 years. 11 years is 4125 days, given the 375 day Athasian Year. A workable number that results in this is 33 days for Ral and 125 days for Guthay”. It makes a year three full Guthays (375 days). The alternative is 25 and 165, which makes a year 15 Rals long, and Guthay somewhat wandering between High Suns.
I’m going with 33/125, with a “year” and a “month” being somewhat independent measures… a year is three Guthays long, but something might be measured in months instead, which won’t precisely match the year.
2 Likes
Yeah, that’s @Rovewin 's website.
A bunch of that material went into our rerelease of Crimson Sphere, and a bunch is going into @Rovewin’s Stargazers of Athas book that’s nearing completion.
1 Like
Based on a number of things I think that the 33/125 works great. The orbit of the moons are never mentioned in any of the products. So you will not find a source for it. It was just never stated. (And what was put in Trade Lords doesn’t work out as nicely.)
While all of the work on that webpage is mine (I try to provide the source when referring to them). However the original 33/125 was from Agantyr’s work in creating the Merchant Calendar.
Prior to leaning about that program I had played around with some of the possible orbits that he was looking at. If you download the program there is a readme file he put with it.
Here is what he concluded:
“Ral and Guthay’s orbital periods are not mentioned in any Dark Sun product that I know of, but given that they only meet in the heavens as full moons once every 11 years, I determined that the most likely periods were either 55 days for Ral and 75 days for Guthay or 33 days for Ral and 125 days for Guthay. However, I quickly found that the former periods repeated too soon, with Ral and Guthay meeting as full moons every 3 2/3 years. That left Ral at 33 and Guthay at 125, moving like clockwork to only meet full once every 11 years. (They also meet as new moons midway through the Endlean Cycle.)”
I pretty much came top the came conclusion and have based all of my stuff about the moons around these two synodic periods. (33 and 125) I try to be precise and provide sources to help people get there too with anything resulting in using them. I recommend downloading that program and playing around with it. I’ve got all the math behind it in a spreadsheet and can pull out all kinds of data with it.
Take a look around my blog, I haven’t done much with it since starting on Stargazer of Athas. But it has few other things you might find interesting with respect to calendars and other info tied to the moons. Let me know if you have any questions. I am still working on finishing Stargazers of Athas which I am sure you will also find interesting. It takes what I did from the website and puts it in a more official book.
3 Likes
I have been looking around it. When I lived in Houston, I gamed with some people who worked with NASA, so space nerdery is meat and drink for me.
What I used it for was, in my Hackmaster conversion, I used the time of Ral’s synodic orbit as a limiter for some of a druid’s powers.
1 Like