Gliese 581-G (Just for fun)

[Podcreature]

true, but how would they know that they have made a revolution? There wouldn't be any seasons or animals migrating or anything they could discern that would indicate a completed orbit around the star. Maybe the moon/moons are the answer to this as well. A Solar eclipse would be pretty interesting for people that know no darkness.



Good point! I would imagine where ever you were the sun would be "north".

Also I think they could use the rings of vegetation as terrain reference for how far away from the sea they are.

Ah, yeah, I keep thinking in terms of an advanced civilization... but how indeed would a less technical people set up a calendar that included the planet's interaction with the sun if there's no change in climate to mark it, and what would be the point? The moon(s), then, would become the most important element to track time. Two moons might help in making that calendar more complex. We might have a calendar that truly omits the entire aspect of years. I was hoping that the orbit might be slightly eccentric, just enough to cause a bit of seasonal change, but they'd be so rapid... A week-by-week rotation almost. The temperatures would be unified, but maybe not entirely. The sun being "north" is very reasonable... I forget the science behind a compass... Just out of curiosity, what would a real compass do on such a planet? It has no poles on which it turns, at least, it turns soooo slowly, the magnetosphere is very weak.

[Raptori]

Compasses point to the magnetic poles, whose position is arbitrary. On our planet it's fairly close to the north pole, but every so often it switches in polarity.

607968main_geomagnetic-field-orig_full.jpg

So their magnets would point to their planet's magnetic pole, and assuming that would stay roughly consistent they'd effectively have two points of reference to work with when navigating. Pretty sure that'd make navigation a lot easier than it is on Earth. I'm not sure if it actually would stay in the same place though...

Multiple moons sounds like it'd be good for the calendar, though it'd be worth using a simulator to work out where they could go without knocking each other out of orbit while still being visible from the planet's surface

[Podcreature]

I suppose that a tidally locked planet does have poles... they turn at the same speed that they rotate around their star, so rotating every 55 days or so produces a very weak magnetosphere, and the problem is compounded by a cooler core, which would further weaken it. thankfully scientists have become optimistic that these planets would develop thicker ozones from the very radiation that would strip them of their atmospheres. This thicker ozone means Earth-like radiation levels on the planet's surface and shields the atmosphere from blowing away. Back on subject though, I guess even if the magnetosphere barely reached above the atmosphere, it would be enough for a compass to detect. Using the planet's poles and the placement of it's sun in tandem with the moons means navigating would actually be pretty straightforward.

And just to throw it out there, there's always sky color as reference. It would be whitish, greenish, blue at the apex, and the further away you go, the more orange/red the sky would become. These sky color zones might be perceived as entirely different "worlds" by primitive people. Governed by different gods or spiritual entities. After all, there would be marked differences in temperature and humidity from one to the next.

I figure the moons would have learned how to get along before recent billions of years... the red dwarf I finally settled on is already 8 billion years old, meaning the tidally locked planet is also most likely very old. I'd assume that they are the product of debris clouds either from the solar system's formation or stuff swept up later over time, and it would have been before life evolved on the planet because as you point out, there could have been serious collisions at that time. Each moon would represent debris that was swept up in it's path, cleaning up it's zone as it formed.

[Podcreature]

Sorry to double-post but I just had a thought for Slylok. One thing that actually might reveal the 55 day revolutionary cycle would be planetary wobble. The sun might wiggle in the sky slightly. Ancient astronomers would have likely found this interesting, if they thought to track shadows, which I'm sure someone would notice the "wiggling" and try it.

[Podcreature]

Just going to follow up with another image. This is the solar-system info I'm sticking into the chart for my species. The text is just there for reference, not the final/actual data. I'm having trouble deciding on names for the planet, moons and star. Pretty sure humans there are calling it "Terra Ocula" (redundant, I know, that's humans for you) ...but the natives would have given it a different name. Not sure what I'll do for background color or effects yet. May just keep gray since it's not distracting.

chart in progress.png

[sangi39]

Just a quick post and run, have to leave for work in the next few minutes:

Earth's magnetic field - Wikipedia, the free encyclopedia

[Podcreature]

Thanks Sangi39! That link also got me looking at the moon's magnetic field more... since it's also a tidally locked rocky planet-like thing with a small molten core. According to your Wiki link, it's the movement of liquid under the planet's crust that creates the magnetic poles. Supporting what scientists say about tidally locked worlds. The core would spin slower, it would in turn be cooler than Earth's. But it would remain to some extent. Bigger worlds apparently have stronger magnetospheres, but I wonder how that scales up proportionally. I guess not only are there weak poles but less tectonic and volcanic activity on this planet.

[JefBT]

Isn't a moon unlikely to happen in this kind of planet?

The planet itself may not have a strong eletromagnetic field to maintain a moon. Maybe some asteroid.

Not only the sun, but the planet's temperature may be it's "north". I mean, hot places, like the center of the ring, would be the "north", and the cold places may be the "south".

The world may be next to some medieval versions, like the flat pizza world, with the "end of the world" as waterfalls to "nothing". In this planet, the hot and the frozen places might be the "end of the world".

[Raptori]

Moons are held in place by gravity not magnetism, so there'd be no problems with having moons

[JefBT]

I forgot about gravity. I was just thinking that it could be like Mercury from our solar system, that does not have a moon.

Thank you Raptori.