Questions tagged [moons]

For questions pertaining to natural satellites, such as our own Moon.

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2
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2answers
188 views

How to get rid of the rainforest for a desert moon with only habitable poles?

I wanna build a habitable desertworld which is a gas giant moon. The desired and already semi-fixed parameters are: mass between 0.4 and 0.25 Earth-masses only 10 to 30 percent global ocean cover, ...
9
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2answers
2k views

Could a planet have a naturally occuring moon at one of its Lagrange points? [on hold]

Would it be possible for a planet to naturally have a moon or large natural satellite at one of its Lagrange points? If so would it then also be able to have a second moon that would be orbiting this ...
4
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2answers
209 views

What would be the effects of replacing the Moon with an Earth-like planet?

Let's assume that for whatever strange -- probably magical -- reason, the Moon was suddenly and instantaneously replaced by a planet identical to Earth in terms of mass and size. Its orbital path is ...
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0answers
63 views

What is the largest amount of natural satellites (with a Hill sphere H1) that can be placed in orbit around a planet with a hill sphere H2?

(If possible, please answer this as a function of the radii of both Hill spheres) Additional requirement: All celestial bodies in this scenario have to have a stable surface and the setup has to be ...
2
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1answer
72 views

If Janus and Epimetheus had moons

Imagine a planet with two moons that have an orbital pattern similar to that of Janus and Epimetheus of Saturn... Is there a way for one of these moons to keep a stable pair of Trojan sub moons? I'm ...
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4answers
195 views

Can huge planets be seen from tiny planets?

Imagine a habitable, water covered, small earth-like orb in space. Let's call it P. From its surface, you see 2 large glowing masses, different sizes, in the sky, let's call them Bs. They are not ...
4
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2answers
173 views

What can my moons be made of?

So I asked a question before about having two moons. A wise patron suggested my moon be made out of something like blown glass, in order to have a big bright moon that isn't too dense. That has me ...
5
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1answer
136 views

How many terrestrial moons can my planet hold?

I have a Gas Giant with 13x the mass of Jupiter. How many satellites of Earth size and mass can it hold safely in its orbit? Edit: This gas giant lies smack dab in the middle of its parent star's (...
7
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3answers
413 views

What's the overlapping calendar of two different lunar cycles

In My world of PD there are two distinct moons, Aurie is a big cream colored moon on a 32 day cycle and Chi is a smaller rust- colored moon on a 20 day cycle. Can somebody help me figure out how often ...
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3answers
121 views

How might wizards figure out how to walk on the moon? [closed]

A group of wizards is currently planning a trip to the moon to study why it makes werewolves happen. They plan to teleport to the lunar surface, do a few hours of investigation (e.g. watch samples of ...
4
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2answers
176 views

If a moon shattered into pieces, what would happen?

Say I have a planet with 10-20 moons of varying sizes orbiting it. If one of these moons were to explode/shatter into tiny pieces (I know this is probably impossible, but if we pretended it were ...
10
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2answers
182 views

How long would this eclipse last?

For a moon orbiting a gas giant which is in turn orbiting a star, I want to know how long the eclipse would last for an observer standing on the moon when the planet passes between the moon and the ...
10
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1answer
166 views

Moons in Binary Orbit

Writing a werewolf story, and decided for a bit of flair, so I wanted two moons in orbit. Did a bit of digging, and I found out that to do that, I'd need to either have them in separate orbit (no ...
31
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5answers
11k views

If Sweden was to magically float away, at what altitude would it be visible from the southern hemisphere?

If a chunk of land mass the size and position of Sweden took off and floated away in a straight line, exiting the atmosphere and orbiting earth, at what distance would it be visible from, let's say, ...
8
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3answers
257 views

Which moon is most favourable as a refuelling station?

My hypothetical gas giant has five major moons. Three of those moons are icy bodies with abundant water ice and volatiles. Any of these could provide fuel for translunar spacecraft, or for spacecraft ...
7
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1answer
141 views

Heating a gas giant's moons in a red dwarf system

Being new, this is my first question. I've read some other posts that gave me valuable insight, but I still have some questions. First, some specifics: Star: red dwarf. 80 x jupiter mass. 3 billion ...
54
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20answers
12k views

What could a self-sustaining lunar colony slowly lose that would ultimately prove fatal?

I've got a lunar colony that was set up to be self-sustaining before a collapse of life on Earth. The colony has survived on its own for several thousand years through a period of technological ...
1
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1answer
162 views

Can liquid water exist on the moons of this gas giant?

This is an edited hopefully more focused version of a question I asked a while ago. I made the mistake of asking too many questions the first time so I’ll try and be a bit more focused here. I drew ...
10
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3answers
2k views

Can a planet still function with a damaged moon?

I'm thinking of having a world that has a moon that's been partially split (so not fully halved) with the debris slowly separating from it. At night you'd see the split moon mainly and lots of ...
7
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1answer
295 views

Brown Dwarf Star vs Gas Giant as parent for habitable moon

I seek to build a habitable moon of a giant planet, thus I looked at the Rouche Limit Equation to figure out how to get the biggest possible Hill Sphere for my moon to exist in. $r_H = a(1-e)\sqrt[3]{...
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3answers
199 views

What international (or in this case, interstellar) laws would apply to the theft of a planet's moon? [closed]

I'm writing a story about a team of rebels and pirates who band together to steal a resource-rich moon from a solar system governed by a corrupt, oppressive regime. Some world context: The moon has ...
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3answers
177 views

What would increasing the gravity of a moon do to its planet?

If I terraformed a moon to have enough artificial gravity/atmosphere to support life, would they end up just crashing into each other? Is there a way to not have this happen, e.g., increasing distance ...
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4answers
2k views

Farming on the moon

Let us assume that I built a dome on the moon's surface. That dome is pressurized and has nuclear-powered lights to deal with the long lunar night (or is in one of the poles). I also have water, ...
15
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7answers
3k views

If a planet has 3 moons, is it possible to have triple Full/New Moons at once?

In the story I created, the Kingdom of Oneirou has 3 Moons--Artemis, Rahu, and Zorya--all of which have their own independent lunar cycles. However, it's officially stated as early as Chapter 2 or 3 ...
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2answers
86 views

A pair of similar celestial bodies coming near each other

In my conworld I have two moons (they could be planets if desired as long as they can stay 'close' to a larger nearby body) of habitable size. I want to reality-check and provide an explanation for ...
11
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4answers
1k views

What factors affect how many moons a planet can have?

A moon is just a natural satellite - something orbiting a planet - so I'm interested in what kind of factors influence how many moons a planet can have, and how many moons a planet will actually have. ...
7
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3answers
1k views

Is it possible to ice skate on an ice moon/world?

If you found out a way to produce a smooth icy surface on an ice moon like Ganymede, Enceladus, or Callisto, what kind of challenges would someone face if they tried to start ice skating? I figured ...
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2answers
86 views

Tides on a Super Close In Moon

I have a moon covered in liquid water that orbits a super-Earth very closely. As you might imagine, the tides are incredibly strong on this moon. However, it is tidally locked and so does not ...
0
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1answer
122 views

What would the moon look like if its orbit was highly inclined?

How would the phases of the moon change depending on the inclination of its orbit with respect to its primary's equatorial plane? Earth's moon has an orbit that is rather close to the ecliptic, but ...
14
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4answers
5k views

Would mining huge amounts of resources on the Moon change its orbit?

Imagine that humanity builds mining facilities on the moon. We know that the moon has Helium-3 which could be used as fuel for fusion reactors. Also, there are a lot of other resources which could be ...
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3answers
143 views

Earth like planet with two moon like satellites

I was thinking about this world with different ancient factions on war. The war caused both of them and most life on the planet to die, I was thinking about one of the moons getting shattered as a ...
7
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5answers
244 views

160 Year Solar Orbital Period & 1.9 Year Moon Orbital Period - Is it possible?

A defining factor of my world is the hardships inhabitants have to face when surviving long seasons. Due to the extreme length of a year, time is largely measured by moon cycles. I need to make sure ...
7
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5answers
288 views

Describing what the world looks like in UV and IR [closed]

In my world I have introduced two super powers, and both can be accidentally acquired by an otherwise normal human: one is to see infrared and the other is to see ultraviolet. I am aiming to have that ...
9
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1answer
195 views

To make a blue moon, what element does it need?

We know that Mars has a reddish color, because its ground consists of iron-based compounds. The moon is grey-whiteish because it consists mostly of silicon-based compounds. What element should the ...
2
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1answer
257 views

Only changing the mass of the moon, how much can lunar mass increase before the Earth becomes uninhabitable?

Bonus: How much would the increase in lunar mass increase average tides? & which factors would cause the Earth to become uninhabitable?
10
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5answers
350 views

Tides with 3 Largish Moons

I would like to have an Earth-like planet (~Earth gravity, ~Earth day, ~Earth year, and liquid water oceans) with extreme variance in its tides. I want the lowest tide to reveal about 30 miles of ...
3
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5answers
267 views

How can this habitable planet have a moon with a naturally occurring atmosphere?

Assuming the planet is earth-like, with more surface water and atmospheric oxygen, and within the habitable zone of a sun-like star, how can a moon orbiting this planet retain a thick atmosphere? The ...
5
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2answers
226 views

What's the biggest, most spectacular asteroid collision the moon could save us from?

An asteroid collision big enough and fast enough to see a massive ejection of rock and moon-chunks, from the surface of the earth AND not wipe out the population of the planet. What size and speed of ...
6
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2answers
150 views

Temperature and climate “under” the gas giant in a tidally locked moon

I've begun the laborious (but fun!) process of putting another world together. Known constraints include: Habitable, (super-)Earth-sized, tidally-locked moon to a gas giant; the giant, where visible,...
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1answer
285 views

In a world with 12 moons but NO sun, how to define a day? [closed]

I made the map of my fantasy world before thinking about the physics, as you can see bellow the art! I'm interested to understand how to decide which moon is in the sky at a given moment, if it's ...
11
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13answers
3k views

How to increase a moon's gravity?

I am building a sci-fi universe where humans have colonized the moons of Jupiter. They are very small and thus have low gravity. In fact, some of them have gravity equal to less than 5% of Earth. ...
10
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4answers
2k views

Could we use both speed and heat to penetrate Europa's ice?

Could we fire a heavy, long (e.g., 50 meters), spear-shaped object into Europa's icy-surface from space and then, when momentum stops, gravity gradually moves weights down inside copper tubes the ...
5
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5answers
385 views

What are the day and night fluctuations for a moon orbiting a planet the size of Jupiter?

In a nutshell, I'm trying to build a world with erratic day/night cycles. To get the erratic days, I'm working with a habitable moon. It takes 3 full earth days (72 hours) for the habitable moon to ...
7
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1answer
184 views

Determining this horseshoe/co-orbital moon's possible orbital periods

I've been working on a system with a habitable moon (Moon A) for a story, and I'm now trying to populate the other moons around the parent planet. I'm considering placing one (Moon B) in a co-orbit, ...
13
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18answers
4k views

How can a moon have an ever-changing face?

Imagine an inhabitated planet like ours with a moon of the same projected size in the sky. The moon has visible structures of colors or darker and lighter areas. Every evening when the moon gets ...
3
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3answers
238 views

How does having 3 moons change a planet?

I'm working on a story that takes place on a world that has 3 moons. At least 2 of the moons are the same size. They align extremely rarely. Otherwise, it's an earth-like planet. There is one ...
7
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1answer
111 views

Co-orbits and Tides

I've seen many questions about tides and tidal variations on a wide variety of interesting single star, multi star, single planet, binary planet, single moon, multiple moon, and even ring system ...
7
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1answer
132 views

Could a Moon have its own “Rings”, like Saturn's, without the Host Planet having them?

I'm currently fleshing out a sci-fi universe and always looking for fun new locales to populate it with, and I saw this phenomenon in a video game I've been playing recently, and it made me curious... ...
29
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5answers
6k views

How deep must be a pit on the moon to hold atmosphere at 1ATM on the bottom

In my world I would like to create a pit on the Moon filled with air. How deep would the pit need to be to get 1 ATM of pressure Could the pit maintain the air or would it be lost to space? If it ...
6
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1answer
353 views

Does my plot point centered around eclipses make sense?

My main antagonist is an infant Great One that's been imprisoned below the Moon's surface and I want its influence and physical form to have a weakness to direct sunlight which, I think, gives me a ...