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Broken/shattered moon?

Discussion in 'World Building' started by cak85, Apr 17, 2021.

  1. cak85

    cak85 Scribe

    As I was writing today, I began to think it would be interesting if my world had a broken moon. As someone with a basic understanding of gravity I am really not sure how this would impact gravity/tides etc? Also how tis would impact the life on the planet?

    I came up with this idea b/c the dominant race on my world are grey skinned giants who worship what they call the Endless Spiral (solar system, stars) and the Origin (sun). In their society everything ties back into the Endless Spiral - their magic, the way they track time, they way though view life and death and spirits.

    So I thought it could be interesting if they believe that the broken moon (they call Broken God) sacrificed part of himself to form the Endless Spiral that has become the stars and solar system.

    This idea is still rough as I just thought of it today so any feedback or questions are welcome
  2. Queshire

    Queshire Auror

    How giant are your giants? 'Cuz if they're big enough then they're already breaking science and you shouldn't worry about whether your moon does or not.
  3. Chasejxyz

    Chasejxyz Sage

    So since this is a fantasy story with magic, you can fudge some of the science for the cool aesthetic, so don't worry about being 100% scientifically accurate. But if the real science gives you some inspiration (especially for different in-world mythologies), then jump right in!

    The prevailing theory of how our moon was formed was that some big thing (like a small planet???) hit the Earth, which threw up a bunch of material into space. Over time gravity either pulled stuff to earth or it accumulated in orbit and turned into the moon. My extremely quick googling says that there is no none moon that has its own moon, but a lack of evidence doesn't mean a lack of [thing] existing. You could also have some "rings" like Saturn, either on your planet or the moon.

    I guess the question is when did this happen? Earth's being struck would have made a giant-honkin' hole in our planet and it wouldn't be very globe-shaped anymore, but that was so long ago you can't see that. If this happened in the recent (cosmically speaking) past, then there should be a visible crater/chunk missing/maybe big pieces floating around. There would be some crazy shadows that will play out on the surface of the moon as stuff spins around and I imagine those would be a huge part of their mythology and superstitions (maybe they believe it's an "animation" of some great battle against Ultimate Evil that created the universe). If this happened in the recent (geologically speaking) past, then the climate is still going to be screwed up. The system is so big and complex that changes take a very long time to "even out," so mass starvation, climate refugees, sudden shifting of arable land to desert...lots of sources of conflict!

    If this happened in the recent (based on regular human time) past (and everyone didn't die from stuff crashing onto the planet) then there's going to be some really detailed retellings of what happened. Think of the The Year Without A Summer: some places saw the volcano explode an entire island, some places felt the shock wave, some places only had a sudden shift of climate that killed all their crops. Everyone would have different beliefs as to what caused it and might not think that other places are feeling something different.
  4. cak85

    cak85 Scribe

    These are really helpful thoughts!

    QueshireQueshire - I imagine my giants to be about 10 to 15ish feet tall. So not really tall but tall enough to be considered giant by human standards.

    My main character comes from a small archipelago of islands in the middle of an ocean. They basically hunt prehistoric-like animals like the mosasaurus (which they call sea-lizards). She basically ends up on an adventure to find her dad but ends up mixed up in a larger scale/world conflict she wasn't ready for. I also plan on having her encounter more typical human sized hominids.

    Yes! I was totally thinking about using shadows as the giants in my story have grey-skinned like thunder clouds.

    I envision this breaking of the moon happening much farther back in cosmic history. The giants are very long lived and count time by spirals, sort of like the Fibonnaci sequence.
  5. Malise

    Malise Scribe

    Not a physicist, but I believe that a fragmented moon would equal lower tides than whole moons of the same size, due to a less powerful center of gravity. So fewer tides, storms, waves, and extreme weather patterns if we're using Earth's moon as a reference point. I have a feeling that a shattered moon would also lower water/land pressure, but I might be wrong.

    In terms of ocean wildlife, we're looking at more animals that have adapted to look more like animals who live in lakes, due to the lack of overall water currents. So less of a need for animals to have min-maxed torpedo-like bodies to efficiently zip against the ocean tides, and more of a need to specialize in tankiness to survive. That of course means your masosarus would totally make sense to exist in a place with a shattered moon, from a world-building standpoint.
  6. cak85

    cak85 Scribe

    Thanks for the feedback! It is good to know that this isn't just another crazy idea haha.

    Honestly, I wanted to create a story where I could include prehistoric like creatures. Even as an adult, I am still like that 9 year old who was obsessed with dinosaurs and other ancient creatures lol
  7. K.S. Crooks

    K.S. Crooks Inkling

    All other things being equal, if the moon is broken but still together/in close proximity then the tides will be the same. If there are two sections far apart then the tides will reflect the size and location of each part.
    cak85 likes this.
  8. Prince of Spires

    Prince of Spires Maester

    What do you mean with "broken moon"?

    If the moon has only shattered into pieces, but they're all still fairly close together and form a sort of ball with gaps in between, then it will not be that different from when you have a solid moon. You could approximate the gravitational pull of that mass of rock by simply adding all the matter together and finding the central point in it. From a distance you wouldn't notice all that much difference.

    If the moon pieces have dispersed and formed a ring around the planet, then their influence on the tidal forces etc will be minimal.

    As for the impact on the planet, it will be minimal. Tides will be lower, but the other two factors which cause them (sun and the planets rotation) are still present. So you will have fewer species that live in that specific habitat. So coastal environments. All the rest would be fairly unaffected I think. Most of the oceanic currents and weather paterns are due to the rotation of the eart and temperature differences between places, as well as geographic features (like mountain ranges, place on the planet, bodies of water nearby etc). They wouldn't change because there is or isn't a moon.

    As for the gravity on the planet, it would hardly be noticable. A moon by definition is minor in size compared to the planet it orbits. So, it's gravitational impact is also minor, similar to how the sun is not really influenced by the existence of the earth.

    A few random points:
    - the earth's moon is as far as we know not the norm. It's fairly big compared to the planet it orbits (it's by far the biggest relative to its planet's size in our solar system).
    - you could research the Roche limit if you want to learn a bit about how moons could disintegrate and form rings around a planet.
    - From what I understand about dinosaurs (which admittedly is not very much), they could grow that big in part because of the oxygene levels in the atmosphere and the average temperature etc, which in part helped plants grow bigger as well. Animal size has little to do with the moon and a lot with natural selection and environment.
  9. John McNeil

    John McNeil Acolyte

    Case 1 - The earth gains a ring. This case arises when the debris will stay in orbit but not be pulled in by the gravity of the remaining moon. Every night is a little brighter. As the ring gets more evenly distributed, tides would become less severe and eventually die out. Check out this Huffington Post article about "if the Earth had rings." Some rings may also help with navigation, making finding north trivial.

    Case 2 - The moon's (or its debris') orbit decays. In which case, the moon (or its debris) will slam (or return?) into the Earth. Any significant portion of the moon that makes it to earth makes the astroid which killed the dinosaurs look like a bug hitting a car's windshield. The moon or its debris kills almost all surface life. Also, global cooling would occur from the dirt kicked up by the impact(s), not that most creatures would be around to complain about it.

    Case 3 - The moon is only temporarily disassembled. If the debris from the shattered moon is still mostly under the gravitational effect of the moon, it'll fall back down and re-form the moon! This may take a while, since the gravity of the moon is weak. The new moon would, most likely, not look like the current one. In the meantime, the tides and most life continues on earth almost like it never happened.

    Case 4 - The moon has gained some energy so it can get out of its orbit. This event looks like it was really, really big. Maybe it gave the moon (or big enough chunks of it) enough energy to get out of orbit with the earth. In which case, the moon will appear (from Earth) to shrink into the sky, until it is gone entirely. Tides would subside. Animals and plants would need to adapt to the new, moon-less world. Over a larger timescale you'd also see a significant increase in the variability of the tilt of earth's rotation, making seasons less predictable and generally making life much tougher - one discussion is this article.

    What would happen to Earth if the Moon was destroyed?
    Sheilawisz likes this.
  10. LAG

    LAG Minstrel

    How big is your planet? How big moon? How dense is the moon's composition? What is the water density of the oceans, depth, atmospheric effect on tides, etc.

    Many factors to consider, what I'll do is skim over them: Here is the planet, oceans can be normal or not, plan grav can be lesser to account for biological continuance of giant bipedal race. Moon can be formed in any one of millions of manners. Few ideas:

    Moon had great oceans, as moon was shattered, great spurts of water followed the fragments into space, and froze. Moon pieces tethered to rocky core by pillars of ice.

    Moon had very dense, gaseous core with gravitational pull enough to keep pieces floating around it, ie. submoons around a gas moon.

    Moon had ppl on it, and a few powerful mages offered their spirits or souls or life essences etc. in a spell to keep the pieces in gravitational synchronicity around a central core, so as to save as many of the moon people as they could.

    Go wild.
  11. cak85

    cak85 Scribe

    Thanks for the ideas. This is really helpful. It honestly just started as - "wouldn't it be cool if the moon was broken and my characters worshiped the broken moon like a god that gave rise to their planet?" For whatever reason - I really like broken, shattered and damaged things in fantasy/sci-fi. I think because it adds some natural conflict.

    I am imagining my world to be comprised of mostly archipelagos with maybe a few smallish continents (like the size of Australia). I like the idea of spread out cultures that mostly develop independently from each other.
  12. Saigonnus

    Saigonnus Auror

    I do love the imagery this concept conjures (kind of like that "Time Machine" movie).

    While I don't think a shattered moon would be too scientifically accurate (given the reasons above), one thing not mentioned is perhaps the planets' gravity captured an oddly shaped/formed asteroid or planetoid (or maybe even a dwarf planet) as a moon (think phobos and deimos) so long ago that it has always been "broken" in the long memories of mankind.

    Another thought that came to mind... what if the moon were volcanically active in eons past? Imagine massive volcanoes spewing long, wide rivers of dark basalt across the relatively light-colored terrain. They could make it look cracked when seen from the surface, but actually it isn't cracked at all.
    LAG likes this.
  13. LAG

    LAG Minstrel

    maybe it's a semi-gaseous, semi-igneous-rock body with a climate and constant volcanic activity. The gasses are denser near the core, so all you see are these chunks of rock coming from an ethereal mist, with constant tectonic shifts, magmic and volcanic activity, and gravitational flux causing pieces to break off, reattach, hurtle off into space, or become so heavy as to descend to the core, slowly being liquefied, then vaporized. This moon attracts other space bodies into its orbit, unless they leave craters on its surface ofc.

    if one wants to entropy extreme the concept, make it that a time shall come when the moon is only gas. Maybe spin prophesy 'bout this into story.

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