Questions tagged [moons]
For questions pertaining to natural satellites, such as our own Moon.
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On Habitable Moon Systems
Context
I was working on a habitable gas giant moon, but I came across an issue in that, at the acceptable distances from its parent planet (10-20 planetary Radii, according to an Artefexian video on ...
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Is it possible to have stable system where the moon of earth-like planet is only visible part of the year from a fixed point on a surface?
Is it possible to have a stable system wherein the moon of an Earth-like planet is visible only during certain parts of the year (seasons) from a fixed point on the surface, mimicking the way some ...
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Could Moon Phases work in a Concave Hollow-Earth?
I'm trying to wrap my head around how phases of the moon(s) would operate in a hollow earth. For reference, I am picturing a situation like this:
In this system, the center of the hollow earth has a ...
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How would a planet's surface be younger than the planet itself? [closed]
Europa, one of Jupiter's moons, is 4.5 billion years old (like Earth.) However, its surface is only 20-180 million years old. What could lead to a planet/moon's surface being younger than the planet/...
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How can an Earth-like planet support two moons of different sizes [closed]
In my world, I need to have two moons orbiting an Earth-like planet. I need the extreme tides as they play a big part for a cultural detail. The first moon should be roughly the size of our own moon, ...
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Habitable Planet with Multiple Moons
I am working on a book with the presence of multiple moons acting as a quasi-astrology based religion whereby the irregular phases of the moons and their relationships between one another allow for '...
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What astronomical situation could account for the PERCEPTION of a very erratic day / night cycle for a planetbound population with limited science?
I would like to create a world that is at a roughly medieval level of scientific understanding and which - as far as it appears to the inhabitants of that world - has a highly erratic day and night ...
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How to find visibility of stars given a certain moon brightness
How would you be able to calculate what magnitude of stars would be visible given a certain brightness of the moon. As I know that the visibility of stars are based on their compared magnitude to a ...
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Question about finding an exact lunar orbit
I am trying to find a precise orbit for a moon that would allow it to always be in an eclipse. So, basically, I need help finding a formula for the semi-major axis and mass ratio that would get the ...
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Red Dwarf Gas Giant Moons?
I'm thinking of an idea for a Red Dwarf star to have one (perhaps even two, but that would obviously be very unstable) Jovian Gas Giants with Mars- to Earth-sized moons in the habitable zone. The idea ...
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Can there be habitable moons despite heavy changes in axial tilt of their mother body?
Ok so i created a gas giant with 10 Jupiter masses and like 9 moons between 0.8 and 1.5 earth masses. All exept the most distanced of those moons are tidally locked to the gas giant and their axial ...
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Can a tidally locked planet with two counter-orbit moons exist for at least 100,000 years?
I believe it is true (correct me if I'm wrong) that a planet with a significant moon such as ours cannot be tidally locked. The orbit of the moon would continue the rotation of the planet and must, ...
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Exomoon Color as Viewed from Planet It Orbits
I have been designing a planet and it has one moon that is slightly smaller than ours. Just like how mars appears red and its dust is red, I realized that maybe if I altered the composition of my moon,...
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Living in natural satellite having an orbital period of 90 earth-minutes to a gas giant that covers all light. How would animal hunters thrive?
Imagine a earth-like planet where life is beginning to thrive at the bottom of the ocean. So far it is an elegant carbon-based lifeform, not different than the one that has burst in our earth.
But ...
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Tide system with two moons
I have a planet with two moons where one moon exactly rotates the earth at earths speed. Means only one side of the planet can see the moon and the other moon will rotate that earth in 45 days. What ...
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How would a moon that was stroking a planet with a tail appear to people on the planet? [closed]
In my world, the moon has heard the poetry and romantic words of a person on the planet, and so has decided to flirt with and stroke said poet with their moon scale tail.
Their tail has magic, and so ...
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How to increase Jupiter’s reflectivity?
The idea of turning Jupiter into a sun to terraform the Galilean moons is a popular one. This concept goes by the alluring name of “stellification,” but has a few important drawbacks when prodded with ...
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Why would lunar megacorps install a government in this scenario? [closed]
The year is 2170. Ish. Humans have colonised Mars, but the planet has yet to rival the economic might of other solar system worlds. As of yet, the main colonial power in the sol system is our own ...
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Efficient ways to keep the moon from receding
Say we decide at some point that we'd like to keep the Moon where it is, stop its recession. What would be some efficient ways to achieve this (in terms of rate of money or energy spent)? The ...
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Orbital limit for a sapient-habitable moon?
How far does a moon need to be from the roche limit for sapient life to evolve?
This is something I've been wondering about for ages. Life on exomoons seems to be a really unexplored subject in ...
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Plant life on a planet with extremely bright "moon"? [duplicate]
The planet in question is part of a Binary Planet pair, both of which are tidally locked to each other at a fairly close distance (~129,000 km) from each other, meaning that the "moon" is ...
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Reverse engineering the Hill Sphere?
I'm wondering if anyone has run into the issue of "I know the general idea of how big my moon is but not the parent planet" and how to sort of reverse engineer finding out the mass/radius of ...
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Would tidal recession significantly reduce the angular size of small moons?
Multiple large moons around a terrestrial planet is something that is seen in science fiction a lot, but is not really easily possible. An alternative is to use smaller moons but have them orbit ...
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Power grid on the Moon
Actually this is not an idea for a book, I thought about it after reading this article. The power grid they propose for the moon would require a lot of electric cables and robots that bring power ...
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Alt-history continuation of Dynasoar program
Just hopping over from SpaceExploration
I'd like to know how realistic a use-case the DynaSoar spacecraft would be for a Titan descent craft, in terms of in-universe realism.
I'm assuming no far-...
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If Titan was suddenly raised to an earth-like temperature, how long before it melts?
After terraforming Mars, humans are now attempting to terraform Saturn’s moon Titan. Having removed much of its dense atmosphere, (reducing the pressure to just 0.7 bars) the colonists have now built ...
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How could I make an earth sized planet with 3 moons work? [duplicate]
Im world building an earth sized planet with 3 moons. These three moons are symbolic in my world with many religions on this world celebrating the number 3 and saying the best things come in 3. I was ...
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How could an Earthlike planet have two moons, one similar to the Earth's moon and the other primarily composed of carbon? [closed]
I am building an Earthlike planet that possesses two moons, one similar to the Earth's in terms of chemical composition and one primarily composed of carbon. How could these two moons form? Which moon ...
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Space Elevator for Ganymede
My settlement on Jupiter's moon Ganymede is to get a space elevator. Unfortunately, I am completely overwhelmed with the math: How long would the cable have to be to the stationary anchor point in ...
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Habitable moon and hycean world [closed]
A hycean world is a cross between a rocky planet and a gas giant. Think an ocean world with an atmosphere full of hydrogen.
Assuming it is in the habitable zone of its star, could a habitable moon, ...
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Geology and tidal forces on moon with Earth-life surface, but very unstable underground
I am writing a story set on a mining colony moon with some very odd geological conditions, and while this idea is admittedly likely impossible to fully make geologically plausible but I wanted to see ...
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What would happen if a Europa-like moon "thawed"? [closed]
I have a planet and moon system orbiting a high mass star, something like a type A main sequence. Everything is only a short two billion years old, but the star is already starting to expand, warming ...
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Orbit of an earth-sized moon around a gas giant planet
I'm working on a world that is the habitable moon of a gas giant planet. For simplicity's sake, assume that the moon is about exactly Earth-size, and the gas giant planet is roughly Jupiter-sized, ...
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Size of a gas giant with an Earth-sized moon
I am working on a world that is an Earth-sized planet that was captured by a gas giant planet moving inward in the solar system, then becoming a moon. Through magic and hand-waving mechanisms, the ...
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Cloud formations on an ocean-covered moon
Vimala is a Luna-mass moon, orbiting a large gas giant in a yellow star system. Though it is two AU from its star, (and therefore outside the habitable zone) tidal heating helps it to support liquid ...
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Possibility of a moon with breathable atmosphere
Imagine you have a world that is earthlike enough for humans (or nearly human-equivalent creatures) to exist on it, so naturally, this world also has a moon.
I imagine the moon to be roughly the same ...
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On the tidal heating of a moon. What is the second Love number?
Years ago it was asked here how to calculate the tidal heating of a moon orbiting another body with a simple equation. The answer is very detailed. They explain the equation, its shortcomings, the ...
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Geological activity and of superearth - cannonball moon system
I understand that this situation is hypothetical -- I just need a piece of advice to make it more realistic.
In my story, there is a superearth of 4,5 Earth masses and 1,35 Earth's radius, rotating ...
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How old must The Moon be?
Some time ago, aliens placed the Moon around Earth with every intent to deceive us about its authenticity, except for the glaring synchronization that allows for total solar eclipses, as something ...
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How close could a gas giant be to my planet without it becoming a moon?
This is an M-type system. Let's take Trappist 1 as an example star (0.0898 Mass of the Sun) and Trappist 1e as an example planet (0.772 mass of the earth, approx 0.029 AU from the star). Assume for ...
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Could a moon roughly the size of Earth's have an active core and magnetic field?
I'm currently working on a project with an inhabited terrestrial planet slightly smaller than Earth, and orbiting it is a moon, which is a similar size to that of Earth's moon. While our own moon has ...
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How stable would partial planetary rings be on Lagrange points?
Context
There's a comparison to what I'm talking about on a larger scale: Jupiter's got its Trojans and Greeks, and Earth does have them too. Those are more or less loose and sparse groups of ...
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How large, slow, and/or close would the moon need to be to block the sun for at least a few hours?
Suppose everything about our world is consistent. I will tweak it from there.
Alternatively, reverse it; suppose the moon was habitable and the planet hostile. How large, etc, would that planet need ...
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What is the difference in speed between my two moons?
The planet in my current project is orbited by two moons, which like Mars' are relatively small and irregularly shaped. The largest moon orbits closer to the planet and the smaller one orbits farther ...
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Jupiter's moon Europa - is it possible to colonize Europa? [closed]
So basically, I have to write a thesis paper because I'm in the last year of high school. It is an independent research project and the culminating work of my studies in school, so it represents my ...
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How would these characteristics of a habitable planet in a triple star system affect the needed aspects of having two moons?
If a habitable planet is in a hierarchical triple star system (not unlike alpha Centauri) and has two moons but has a large torrid zone, what characteristics would my moons need to have in terms of ...
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Tides in this planet-moon system
So, we have an imaginary super-earth planet twice the mass of earth, but with a density and volume meaning experiences only 1.05 g surface gravity. This planet has a single Luna-mass moon that orbits ...
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How can we move the Moon into a more distant orbit by using electrostatic charge?
Earthers wish to change the Moon's orbit in order to adjust the length of a lunar month. They intend to do this by giving the Earth and the Moon equal electrostatic charges thereby pushing them ...
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Could a planet have 1/2 the Earth’s mass but 1 g surface gravity?
So, we have a captured planet/moon orbiting a gas giant in the habitable zone. It is akin to prehistoric Mars, its geological activity having been maintained by constant tidal flexing from the gas ...
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What effects would a Jupiter-like gas giant's magnetosphere have on a human civilization on its habitable exo-moon?
Background:
Like many others here, I'm building a world for a story I'm writing. I'd like it to be taken for granted that a moon roughly the size of Earth that is habitable for humans could exist in a ...
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