Questions tagged [moons]

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

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120 votes
7 answers
43k views

How would having multiple moons affect tides?

We know that planets can have multiple moons, sometimes quite a few (like Jupiter). Assuming that a planet with several moons were habitable in the first place and has significant oceans (greater ...
Monica Cellio's user avatar
41 votes
3 answers
12k views

Habitable moon of a gas giant: working out the sizes and distances

I am attempting to create fictional, stable P-Type binary system, featuring a gas giant in a stable orbit, with a habitable Earth-like moon. “Is a Jupiter-sized planet plausible in a habitable zone?” ...
platypus-rising's user avatar
27 votes
5 answers
3k views

Can you add a mini moon to Earth?

So we have had multiple questions on having multiple moons and this is another. I did check and didn't find questions that covered this specific setup. I have an earth-like world I am working on, ...
James's user avatar
  • 32.9k
35 votes
6 answers
6k views

What's the smallest reasonable natural planet or moon with Earth-like surface gravity?

We all know that equation for surface gravity is $$ g = \frac{4\pi}{3} G \rho r $$ So if we want Earth-like surface gravity of $ g = 9.81 $, then the equation for radius is $$ r = \frac{3 g}{4\pi G ...
Mołot's user avatar
  • 33.3k
32 votes
8 answers
7k views

Can we 'beam' energy from the moon?

Really can't believe I have to edit this in, but this question has no bearing on our current use and generation of nuclear energy on Earth. There are dangers to nuclear energy generation, or we would ...
Twelfth's user avatar
  • 24.3k
63 votes
16 answers
9k views

Speedrun to the moon in one lifetime?

Imagine you have a large population of adolescent humans (as large as you need) on a completely uncultivated Earth, initially containing no artificial structures whatsoever, only natural resources. ...
Franklin Pezzuti Dyer's user avatar
16 votes
10 answers
8k views

Could humans alter the moon's orbit significantly with current technology?

A terrible virus has made most of the populations and government officials of the largest superpowers on Earth stark, raving mad, without depriving them of their intelligence. They have decided that ...
Fiksdal's user avatar
  • 2,103
13 votes
2 answers
1k views

How can you make a stable configuration including a moon that has a moon?

A moon is, fundamentally, a rock that's caught in the gravitational field of a bigger rock (a planet) and drawn into an orbit. Some of Saturn's moons, for example, are speculated to be debris from ...
Monica Cellio's user avatar
11 votes
7 answers
4k views

Would it be possible to terraform the moon?

I have a "simple" question that is the basis for an idea I'm developing: Is it possible to terraform the moon and, if so, what type of technology would be needed? I understand that this isn't the ...
JasonWilczak's user avatar
8 votes
3 answers
1k views

Captured Earth-Like Moons around Gas Giants

Is there a limit (and if so, what is it) to the size (mass) of terrestrial planet that could be "captured" as a moon by a migrating gas giant? I'm writing a novel where a colony ship crashes on such ...
scicurious's user avatar
50 votes
4 answers
6k views

Moons of Moons of Moons

My question is simple: How many nested moons are physically possible? If our moon had a moon, that would be a nesting of 1. I'm assuming it's easily possible for a really big moon to be orbiting a ...
Varrick's user avatar
  • 3,683
7 votes
5 answers
2k 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 ...
Firelocke's user avatar
  • 1,260
5 votes
2 answers
3k views

I'm building a fantasy world like Earth but it has two moons adjacent to each other in a co-orbital configuration and need help

I am looking for help on the following: Will that have any affect on the length of days and nights? Would having two moons create a higher body of water on the planet due to increased tides? (i.e. ...
user31604's user avatar
5 votes
3 answers
1k views

Naturally making a gas giant moon habitable

Let's say that in my planetary system there is a gas giant around the size and distance from the Sun as Jupiter. I need the planet to be similar enough to earth to be able to be inhabited natural by ...
TrEs-2b's user avatar
  • 56.2k
2 votes
2 answers
17k views

How much TNT do you need to blow up the moon? [closed]

How much TNT do you need to blow up the moon if you place it exactly in the middle? Just think of the explosion -- that there's no air in space doesn't matter! What do you think is it possible and ...
Stefan's user avatar
  • 661
28 votes
5 answers
7k 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 ...
Igor Novelli's user avatar
24 votes
5 answers
6k views

What would a habitable moon most probably look like?

We have a pretty good idea of what attributes a planet would need to sustain life and one can imagine how life might develop on a planet, even in difficult environments. I find it extremely difficult ...
Tonio's user avatar
  • 341
21 votes
1 answer
2k views

Can a habitable moon rely on the magnetosphere of its parent planet for radiation protection?

Science-based answers, please. Key points: the main concern is radiation protection for sustainability of human life (and accompanying plant and animal life ecosystems, whether earth-like or not). ...
Harthag's user avatar
  • 4,133
20 votes
1 answer
3k views

How does one calculate the tidal heating of a satellite?

I've been searching for hours, and most formulas I can find use complex/imaginary numbers or variables that I don't know or can't find out (such as the imaginary part of the planet's love number, ...
Alexader Ferguson's user avatar
20 votes
3 answers
4k views

Tidally locked gas giant moon - brightness of the gas giant

Imagine a tidally locked gas giant moon, which is otherwise earth-like. One side of the moon will have a huge planet constantly hovering in the sky (24 hour day/night cycle with a Jupiter-sized ...
Korvas's user avatar
  • 803
20 votes
7 answers
6k views

How would a planet-sized computer power receive power?

Imagine: A Kardashev Type I civilization mainly resides on a planet analogous to Earth, with one moon, analogous to Earth's moon. Eventually, the society grows so complex that machines filling space ...
Zxyrra's user avatar
  • 20.6k
19 votes
4 answers
2k views

Earth-like Moon around the Gas Giant. Eclipse length?

Worldbuilder in dire need! I'm trying to figure out the eclipse length of a habitable Earth-like moon that is rotating around a gas giant. The story that I work on is centered on the Earth-like moon, ...
Jotunn's user avatar
  • 616
18 votes
8 answers
6k views

Is a moon inside a hollow Earth possible?

The Hollow Earth theory is/was a pseudoscientific idea that our world is actually on the inside of a large sphere. The "sky" points inward towards the center, where the "Sun" (a light source) is, ...
HDE 226868's user avatar
  • 101k
18 votes
5 answers
7k views

By what mechanism could a planet be locked into permanent solar eclipse?

I've got an image in my head of a world where it's just normal that the star is black with a golden halo around it - in other words, where the planet is in a state of perpetual solar eclipse. Are ...
Nerrolken's user avatar
  • 3,568
15 votes
7 answers
2k views

Could a moon have its own satellites visible from the planet it orbits?

Say you have a planet and the planet has a moon: could the moon have visible satellites as well? I don't mean a gas giant planet, I mean something habitable by humanoids or humans. Will the moon's ...
Aeolanyira's user avatar
12 votes
6 answers
3k views

How can I set a moon on fire?

So, for reasons which may or may not pop up in a later question of mine, I need to light a small Moon-like moon on fire. Well, sort of. See, I need a small object capable of emitting a lot of light - ...
HDE 226868's user avatar
  • 101k
9 votes
3 answers
398 views

Habitable environment on a big moon of a gas giant lacking magnetosphere

I am trying to figure out how to make a moon (75% of Earth size) of a gas giant habitable. To give an idea of the technological level, here are technologies the colonists have access to: fully ...
Olga's user avatar
  • 4,543
4 votes
4 answers
7k views

Is it possible to have a non tidally locked moon?

Fo my question, I'd like the moon to orbit around a saturn-like planet without rings. This moon would be located at a million kilometers away the host planet. the moon's size would be about 12 000 ...
Mathis's user avatar
  • 361
2 votes
2 answers
619 views

The major effects on the habitability of exomoons orbiting this Brown Dwarf

I'll need to give some background to this question. I'm interested in the idea of a densely inhabited star system, and having large exomoons is one way that they can all orbit roughly at the same part ...
Axion's user avatar
  • 1,154
13 votes
9 answers
4k views

Could a moon made of fissile uranium produce enough heat to replace the sun?

This was my answer to this question: Retrofitting geocentrism - what replaces the star? I spent long enough on it and got an interesting enough result that I wanted to share, so that it might be a ...
user avatar
63 votes
20 answers
13k 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 ...
aaronius's user avatar
  • 621
35 votes
7 answers
5k views

Can a radioactive moon affect life on a planet?

This question is meant as a reality check on this answer to The land grows evil and corrupted ... but why? Radioactive moon in a nearly geosynchronous orbit. It slowly kills or alters all life ...
Mołot's user avatar
  • 33.3k
30 votes
12 answers
6k views

How to wrap the Moon in plastic to make her a giant, supported by the atmospheric pressure, greenhouse

Moon's surface is about thirty million square kilometers large. That's a lot of plastic, but no bigger effort than many other terraforming projects we have discussed. Description: A global bubble ...
Ginasius's user avatar
  • 1,346
24 votes
3 answers
4k views

Realistic sky of an Earth-like moon orbiting a gas giant (length of day and size of celestial bodies)

I'm trying to work out what the sky looks like on an Earth-like moon, in particular the length of day and apparent size of the other celestial bodies: the gas giant's size, the gas giant's other moon'...
Udon Nomaneim's user avatar
17 votes
7 answers
5k views

How to flood the entire lunar surfaces?

Given that the surface gravity on the Moon is a fraction of Earth and there is virtually zero atmospheric pressure but I still want to wet our beloved moon with whatever liquid that is known to ...
user6760's user avatar
  • 47.9k
15 votes
3 answers
2k views

What is the largest possible appearance of a celestial body in the sky?

In SciFi Art we often see planets/moons/stars fill enormous amounts of the visible sky. I'm wondering what the theoretical limit for this is realistically, since there are maxima for the possible size ...
fgysin's user avatar
  • 3,240
12 votes
4 answers
2k views

A world with a moon orbiting much closer than ours

The world I am envisioning is a rocky planet with oceans, plate tectonics, atmosphere, and several other similarities to our globe. The mass and size is roughly equal, but its moon is orbiting much ...
fantasia's user avatar
  • 734
10 votes
2 answers
1k views

How large can an apparent size of a moon be?

In a lot of media one can see moons or other planets that cover a significant portion of the sky (like the background on this page for example). This could be because the moon is actually large or ...
Maxim's user avatar
  • 1,955
8 votes
1 answer
470 views

Multi-planar planetary rings

According to this Reddit conversation, the detritus around a planet tends to form into a single plane located around the equator given enough time. How long does this process take? Suppose a planet ...
Frostfyre's user avatar
  • 25.2k
8 votes
3 answers
632 views

How to blanket moon with a permanent atmosphere?

There exist numerous theories on why the Moon lacks a layer of air if any, however the main culprits are gravity and the lack of Geo-dynamo simply put the Moon does not have the necessary mass nor the ...
user6760's user avatar
  • 47.9k
7 votes
2 answers
1k views

Tidal forces of tidally locked moon orbiting a gas giant

My setting is a habitable moon with freestanding water orbiting a gas giant. Originally I thought the gravity of the jovian world would tend to draw water toward the tidal bulge of the moon itself. ...
Christian Meador's user avatar
7 votes
3 answers
832 views

Earth with planetary ring

I imagine that if we could transform the Moon into a beautiful planetary ring around Earth, wouldn't it be spectacular! Problem is the feasibility. Are there any practical solutions? Option I think ...
user6760's user avatar
  • 47.9k
7 votes
3 answers
3k views

Will moons orbiting gas giants always be tidally locked?

Inspired by this article about the Kepler-enabled search for life-supporting moons, I came over here to learn more about the concept. I found this very complicated answer to a very complicated ...
J.D. Ray's user avatar
  • 1,668
5 votes
4 answers
524 views

Can a robot experience an identity crisis (which is not by design)?

For those (readers) who have seen the blockbuster movie titled I, Robot (2004 film) there is a humanoid robot who prefers to be called Sonny: Clearly this implies that Sonny is different from the ...
user6760's user avatar
  • 47.9k
4 votes
3 answers
245 views

Would a small low gravity moon be able to harbor complex life?

I was thinking of creating a moon that has low gravity which allows trees to grow extremely tall and would make for an interesting ecosystem. My question is would a relatively small moon with less ...
GreatGuardian's user avatar
101 votes
6 answers
23k views

Would a Moon made of water pose a threat to Earth during eclipses?

Is a moon made entirely of water possible? Could a planet made completely of water exist? I was inspired by the above questions to ask the following: Assume that our current Moon is replaced ...
chasly - supports Monica's user avatar
34 votes
12 answers
8k views

How would one design an undetectable nuke to hit the Moon with?

Colonists have set up a viable, long term lunar colony on the near-side of the moon in the mid-21st century. They are quickly reaching total self-sufficiency and the earth governments who sponsored ...
Green's user avatar
  • 52.8k
32 votes
11 answers
8k views

What skin colour would living permanently on the moon select for?

The context: There is a population of people surviving on a lunar-analogue's surface, descended from the crew of a crashed spaceship. The rest of their society is not relevant to the question, but ...
Ynneadwraith's user avatar
  • 8,066
22 votes
15 answers
4k views

How can a spaceship unknowingly interfere with tides on a planet?

I've asked before about my polytheists with competing moon gods. I now have a better understanding of how tides -- a very visible manifestation of lunar influence -- work with multiple moons (thanks),...
Monica Cellio's user avatar
22 votes
14 answers
5k views

Always a full Moon for the Emperor - Can this be achieved with solar panels and LEDs?

The Emperor of the World wants there always to be a full moon. His Scientific Advisor (the SA) comes up with a plan. He plans to cost out the venture, hand it over to the Keeper of the Treasury who ...
chasly - supports Monica's user avatar