Multiple moon phasing...

[Grimslade]

Ok... the planet has three moons. A, B, and C. A is closest and the smallest. B is inbetween, in both orbit and size. And C is the largest and furthest away.
Lets say Moon C orbits every 60 days.
To me, that would mean that Moon B would orbit every, say... 45 days. And Moon A every 30 days...
Does this sound logical? Possible?
In order to know each moons phase and thier relationship to one another, I would need to sit down and figure each one out over the course of its orbit, correct? Make a calander and write down each New Moon, etc... ?
Id just like to know if Im on the right track. All of that seems logical to me.

 

[MrNybble]

Size and density of a moon also determines the orbit time along with its distance from the planet. Captured moons have different properties of formed moons. Keeping to the strict logic of science makes for many variables to consider. Throw in some magic shenanigans, and you can say the moons are actually one moon just in three spots at the same time. What is the orbit time of the planet in terms of days and years? More details about this moon project please.

 

[Grimslade]

Thanks for your input. The magic idea is intriguing, to say the least. Thats a very cool line of thought.
Well, Ive been toying with an idea of a planet larger than Earth with three moons... Most likely they are smaller than ours, but I dont know yet... Sailing from continent to continent during certain times of the year is jmpossible because of the massive storms at sea. Or... certain oceans during certain times of the year. However, the same lunar pull that sets some of these storms off, also keeps them out at sea. So... F5 hurricanes can be frequent but hurricanes coming ashore is not. Not sure that is possible... unless, maybe, I just say that it is! Ha.
Ive been thinking its in a much longer orbit around the sun than we are. Say, three or four years to our one.

 

[MrNybble]

Only one sun? Kidding. Not like I could talk much with world building a solar system. There are enough notes on my plants, moons, and star to make a separate book. It took years to fluff that beast out when ideas came to mind. Sadly, most of it isn't used in my stories as it's not needed to drive to the story. Still had fun thinking of it.

Having all these unique elements of a non-earth planet opens up some new writing avenues. If you really want to pump some science behind having multiple moons, there are many things they influence. Weather being one as you said. Culture could be another. A moon can have a geosynchronous so it looks like it never moves. Some part of the planet's populace wouldn't see that moon. Imagine having people that worship moon gods and find out there is another moon. That would just mess with established lore for any culture. Explaining the new time thing with readers as years, months, days, hours, minutes, and seconds are now all different will be a challenge. So many possibilities.

 

[Saigonnus]

Your world is like mine in that it is slightly larger than earth, and has 3 moons. The truth is, I didn’t do a lot if research in regards of composition, distance etc. Mostly because it is the latent magical fields that hold them in place.

I describe the closest as a green jewel that brightens the night. It is perhaps 1/4 larger than our moon and is a habitable (and inhabited) forest moon.

The second is a ball of blood, a desert moon that thus far is inhabited, could change though, given that it does have a light atmosphere (think 50% of Earth).

The third is revered as an omen of good fortune whenever it is a full moon, because it is a silver ball of ice that looks like a silver coin, even to the ragged figure visible (not a face, just a darker section of deeper water? frozen over.

It has an atmosphere much like Mars, so isn’t habitable.

The interesting thing about mine is when the fields interact, portals are created that permit 2-way travel to/from the forest moon, the only one close enough to “rub” against the planetary field.

 

[Night Gardener]

Ok... I'm going to let my thoughts wander a bit because this is fun to think about...

Make a lunar calendar, for certain... and with this calendar, be prepared to make some charts and some notes for further preponderance. Overlapping orbits should definitely be noted and developed for their phenomena.

The biggest thing to consider, is Gravity.

You have three moons, in an eliptical orbit (not low geosynchronous, like a modern launch tech satellite) around your planet. Their individual gravitational pull on the planet, depending on their mass and distance, will make for some interesting conditions depending on the planet's position to the 3 moons. One moon's orbit in relation to the other 2 moons and to the planet will also make for some phenomena.

I'm sure someone more scientifically inclined than myself could do the hardcore calculations, but these are the ..."relativities" to keep in mind.

If your moons are too close to each other, over time, you can end up with a slingshot effect or a randomized orbit of one or more of the moons. If it gets too close to the planet, that's obviously cataclysmic. If a moon eventually gets slung or spins out too far too be recaptured by the planet or the other moons, it would be extremely impactful, likely carastrophic, on the planet's biosphere.

Now, you also have to imagine an orbit pattern where they aren't on a tratrectory to inevitably collide. (Or, you could, if that's what you're going for.) So, 3 moons sharing the right ratios of "close enough to orbit a planet, but not too close to each other to maintain a predictable, non-disasterous flight plan" should probably be pursued.

Someone mentioned a 'captured' moon scenario... and from what little I understand, a small celestial body cruising a solar system, after being flung from somewhere else, might be drawn in by a planet. But, if a moon or two was already in place, that might destabilize the whole orbit for the moons and the planet. I think scientists have come to the conclusion that the most stable orbits arise when the planet and it's moon are "made" around the same time. They hypothesized that a rogue celestrial body impacted our coalescing planet rather early in the formation, and knocked off a chunk to form the moon. The impact debris flew into space, but as fast as it traveled away it was being drawn backwards. Which they have also suggested that our planet will, eventually' lose our moon. It was formed by the inertia of "leaving", and little by little is drifting away. The flipside would be drawing the moon in too close and impacting the planet... which would probably throw off some more cataclysmic debris to form new moons. But I digress.

Now, as a person looking up towards the sky... what do you want your characters to see? I think it would be kinda cool to have one moon you could easily see during the daytime, like a false sun. We see it occassionally here on earth, and with 2 more suns it seems likely that phenomenon might happen more regularly. And, if the moons themselves rotate on an axis, you might get a 'clock-like' effect where certain times of the day (or night) can indicate the passage of time because the "face" of the moon changes. That could be fun. Eclipses might be far more common, too.

The big thing you'll have to take into your calculations, is the tides, weather and ionosphere*. Do your moons, if alike in mass and distance, work on opposite sides of the planet? If so, your tides might be weaker. Or stronger. Think... kind of like balancing a teeter-totter. We have tides because the planet rotates on an axis, and our singular moon orbits around the planet. So, if there were 2 more moons in that equation, high/low tides could be more frequent, possibly more extreme. Maybe there's 3,6,9...tides every day. How would life evolve under those conditions? Multiple tides effect weather patterns, moving volumes of water into warm shallow areas and back to cold deeper areas, changes rates of solar evaporation. Your storm systems might be rather radical. Perhaps, more humid of a biosphere overall.

With 3 moons running interference from the sun, your planet might have different atmospheric conditions. If there's more moons, more solar radiation gets deflected away from the planet. Not sure exactly how your planet's magnetism might be impacted by extra moons, but the magnetic field is crucial to maintaining the biosphere. So... maybe your planet doesn't have the regular occurrences of aurora borealis, because not as much radiation penetrates the ionosphere. Not as many pretty light shows. What a pity.

Oh, and let's not forget starlight! With extra moons knocking about, stargazing and navigations might be a bit trickier. If there's always a moon out somewhere, or all the moons get refractions from the sun at the same time, your characters might have a harder go making accurate or highly detailed observations with moonbeams shining back into their instruments. However, stable orbits of moons could lead to different navigational techniques.

3 times the moon could also mean 3 times the moonbeams. Maybe, a full moon for 3 moons is REALLY bright. How would that effect evolution and culture, where a full moon might feel more like a dusk or dawn?

I'm going to stop here for now. There's some fun stuff going on here.

 

[Grimslade]

Again, thank you all for your input. I really appreciate it.
Ive come to believe that a person could spend weeks working out the proper orbital mechanics and relationships between stars, planets, moons, etc (unless, of course, your an astrophysicist), and there may be stories or rpg scenarios where thats necessary. (?)
In my case, Ive decided its not. So much.
Im going to take my ideas and flesh them out in, hopefully, fairly easy to understand and logical ways.
Ive decided to go big or go home, so to speak. Its what Ive always wanted to do. A large planet in a binary star system with multiple moons. To me, its the ultimate fantasy landscape. The orbital mechanics are very difficult though, if one wants to get it... close. Going smaller and... more basic, is easier... but not what I really want.