Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [moons]

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

12
votes
3answers
2k views

Gravitational anomaly (Mascons) creating water-hills

A scenario in the far future -- The moon has been successfully terraformed. All problems have been worked-out, from flinging volatiles into collision course with the moon, up to creating and retaining ...
1
vote
2answers
67 views

What would be the mathematical formula to figure out a person's weight on a world bigger or smaller than Earth?

Okay, trying to figure out this math guys! This may be simple math to some of you, but not me!!! I googled various ways of asking this question and got some good results, but I'm looking for a simple ...
27
votes
12answers
9k views

Would gas giants work as waste disposal sites?

In my novel, the many moons of Jupiter and Saturn have been colonized, but I'm running into some logistical problems - namely, waste disposal. My first instinct was to dump it on-moon; while this is ...
3
votes
1answer
65 views

Can giant planets in the habitable zone have rocky moons?

My question is in the context of a fictional super-Neptune that lies in the habitable zone of its host star system. Giant planets only form beyond the Frost Line of their protoplanetary disk, and ...
22
votes
13answers
4k 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 ...
91
votes
6answers
21k 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 ...
10
votes
6answers
883 views

How can spacecraft manufactured on the moon be powered?

Background: The moon has been selected as the base for human space exploration. Rather than ship tonnes of material out of earth's gravity well, interplanetary space-craft and space stations will be ...
1
vote
4answers
133 views

Moon take off without rockets

Take-off in a craft with rockets allows a gentle acceleration that doesn't kill the occupants. Given that the Moon has no atmosphere: Is there any current technology that would allow safe takeoff ...
7
votes
2answers
127 views

Could the TRAPPIST-1 planets have moons?

The TRAPPIST-1 planets are all very close to each other and thus are subjected to strong gravitational forces amongst each other and to the red dwarf they're orbiting. Would it be possible for them to ...
5
votes
1answer
255 views

Is there a relationship between apparent moon size and orbital distance around an earth-analogue?

I would like to give my imaginary earth-analogue planet multiple (natural) moons. Is the orbital period of such moons at all related to their size (or apparent size)? In other words, am I free to ...
3
votes
1answer
91 views

Could this moon of a gas giant orbiting a neutron star support life?

Making the following assumptions: 1. The three moons of the Gas Giant are safe enough distances from and massive enough not to pull each other apart or send themselves careening into the void. 2. ...
0
votes
0answers
41 views

How would an extra moon affect the tides? [duplicate]

In my world, I'm planning to add a second moon which would be positioned closely to the first. I was wondering what effect would that have on the tides?
2
votes
1answer
268 views

Feasible star + planet + moon combo? Did I miss anything that makes this system wildly unstable or otherwise impossible?

Here's what I've come up with: The star: A main sequence star, roughly a sol analogue Younger than Sol (say 3-3.5 billion years old) roughly the same starting mass as Sol, but has had less time to ...
2
votes
2answers
123 views

Earth Orbit Extreme Change

So recently I got slated for missing some glaring obvious flaws in my story on here, which I really do appreciate. I'm approaching the question from a different angle though, in two parts. What ...
-1
votes
1answer
98 views

Earth Exploded, Orbiting and double moons

I have a scenario which I am too poorly knowledgeable to address, I'm hoping for some expert input. I'm currently writing a novel, in which a large section of Russia/EU continents were blown up in a ...
3
votes
1answer
150 views

Can Europan ice cracks sustain complex ecosystems?

Europa's surface is marred with huge, curved cracks, called lineae, which may - depending on the thickness of its icy crust - expose the subsurface ocean to sunlight. Pictures like the one above (...
-1
votes
1answer
119 views

How would the transfer of mass from the Moon to Earth change the rotation, orbit and speed of the Moon and Earth?

I've read the creation of dams in Earth can change the speed of rotation of the planet because they reallocate the mass over the planet. Let's suppose humans find a valuable mineral in the Moon and ...
8
votes
3answers
284 views

What is the maximum orbital time for my moon around my planet?

I fear the math involved is beyond my capabilities on this one. I have what I consider to be more than a Layman's understanding of the physics involved, and I believe I can follow the math well ...
7
votes
1answer
627 views

Massive tides and resources

Assuming a situation similar to this, where the moon causes slower but massive tides that slowly encircle the globe. Would the poles be constantly underwater or not underwater (like A or B below)?: ...
4
votes
2answers
471 views

What would happen if a little less than half of the moon crashed into the Atlantic ocean? [duplicate]

Let's say an asteroid hit the moon and broke it in half. One half remains where the moon usually is relative to Earth, and the other half is flung at Earth near the equator, in the Atlantic ocean. ...
9
votes
3answers
169 views

Is this planetary moon's calendar possible?

I'm attempting to create a world that has very brutal, hard swinging weather and environments, leaving much of the planet desert-like. The world I've designed is a moon of a gas giant. The Parent ...
8
votes
1answer
149 views

What kind of Gas Giant has a “safe zone” between the radiation from a star and the radiation from a gas giant planet?

This is a progression from my first question, here (if this is too similar to my original question, please let me know of a better way to address this, as I am not getting the answers I need on that ...
-1
votes
2answers
169 views

Characteristics of a habitable satellite planet [closed]

In Habitable Planets for Man, Stephen Dole establishes that a satellite planet in orbit around a massive gas giant, (like Jupiter's Titan, I guess) would be habitable for humans. What would it be ...
12
votes
11answers
5k views

How can Ganymede have an Earth-like gravity without us having realized it?

Imagine a small primitive humanoid civilization that developed independently in caves under the surface of Ganymede. We can assume there's enough light that filters through the crystalline surface to ...
13
votes
1answer
234 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). ...
1
vote
1answer
169 views

If Earth's Moon Were Ganymede-Like, Part I: Rotation

I know that in the past I posted questions on if specific bodies larger than the moon--Mars in one and Titan in another--but this series deals with questions regarding Earth's effects by a natural ...
6
votes
1answer
172 views

Geostationary moon

My planet is very Earth-like with a day length of 26.87h. The moon has a radius of about 1550km, a mass of $5.2\times10^{22}$ kg and orbit 45500 km from the center of planet. My scenario is that the ...
10
votes
3answers
308 views

Could I use a series of magnetic asteroids to create a magnetic field for mars?

If I push a couple of magnetic asteroids into mars gravitational field, could they form an interlocking series of magnetic fields able to protect mars from solar winds? Size limits for asteroids is ...
13
votes
5answers
2k views

Why did US government hide the discovery of an ancient civilisation on the moon? [closed]

July 20, 1969, Neil Armstrong sets his foot on the moon surface. He declares : "That's one small step for [a] man, one giant leap for mankind". But what history books don't mention is that, as he ...
14
votes
8answers
1k views

How to explain life on a moon orbiting a non-habitable planet

For story purposes, I am building a world where all life exists on the moon of a non-habitable planet (the moon is not tidally locked). How can I explain this in a convincing and mostly scientific way?...
5
votes
1answer
96 views

Is it possible an ice line from pole to pole in a tidally locked Earth-like moon?

I am aware that there are a lot of answers explaining the fundamentals of a tidally locked "Earth-like" moon around a giant gas planet. For example this one: Habitable moon of a gas giant: working out ...
1
vote
3answers
174 views

How big does a moon have to be to have the earth locked to it?

I would like a earth-moon system like Pluto-Charon (but with earth instead of Pluto) where both will be tidally locked to each other within something like 3 billion years (before complex life appears)....
4
votes
2answers
98 views

Conditions for an Ice Covered Moon to survive around a Terrestrial Planet

In my fictional setting, the planet that people live on, called "Nearth" has one smallish very dark moon close in, and a large moon farther off with a very high albedo. Nearth is exactly the same as ...
3
votes
1answer
72 views

Consequences of a two-mooned system losing the one closest to the planet?

I was thinking of adding rings to my planet and I wanted to give them a proper origin, so I thought about getting rid of the moon closest to the planet since I would still have one and it could make ...
1
vote
2answers
175 views

Would the Earth with 4 moons still be habitable?

I'm currently writing about an Earth sized planet that is 33% water and has 4 moons all the same size as our moon. All moons are 243,000 miles from the planet's surface and the planet takes 392 days ...
4
votes
5answers
195 views

How would I make a moon appear black in a night sky that has a nebula visible in it?

So, I'm developing a world for my fantasy setting, but I thought it'd be neat if this particular world had a nebula visible in its night sky. (So, it might not be a nebula like the kind we have in ...
2
votes
3answers
178 views

What should the size of my moons be?

(Not entirely sure if this is the right place to ask this but hopefully I'm right!) I'm writing a novel and the planet this novel takes place on has two, twin moons of approximately the same size. ...
2
votes
3answers
137 views

Capturing a moon: Process reality check

Background: I have an icy moon on a collision course with my fantasy world. Mages on this world have the ability to slow the speed of the moon gradually. I want them to use this power to lock the moon ...
9
votes
3answers
214 views

Lifetime of the Moon's moon

Imagine if the Moon had its own moon. A moon (likely an asteroid) that lies within the Moon's Hill Sphere. I have read elsewhere about the fate of such a moon. Over time due to the Moon being tidally ...
1
vote
1answer
95 views

What happens if a small moon is held within a planet's Roche Limit?

For story reasons, I need my mages to convert a moon on a collision course with their planet into a ring around the planet. The only thing they can do is hold the moon still. They can't do so ...
6
votes
1answer
50 views

Which side of a tidally locked moon experiences higher radiation?

Looking most specifically regarding the moons around Saturn, Jupiter, and Uranus. I've been unable to get a concrete answer on this through various sources. I've actually read several articles briefly ...
1
vote
2answers
124 views

Added Difficulties of Space Flight on Gas Giant Moons?

What additional difficulties might the inhabitants of a gas giant moon face when attempting to launch spacecraft beyond their moon's orbit, especially beyond the planetary system? I presume that they'...
-1
votes
4answers
184 views

Would a moon shatter if it collided with an unmovable barrier?

For story purposes, I'm trying to determine what would happen if a small moon-sized object crashed into an unmovable barrier surrounding a planet. My goal here is to eventually get a ring surrounding ...
1
vote
0answers
89 views

Number of planets in a habitable zone with large moons [closed]

I recently had an idea, and it involved moons. Excluding gas giants, roughly what percentage of planets in the habitable zones of their stars would have large moons like Earth does, as opposed to Mars ...
3
votes
2answers
132 views

Lunar cycles for a two moon planet (one of which is smaller and orbits the first moon)

My planet, is roughly as big as Earth, but has two moons. The first moon, Luna, is essentially the same as Earth's moon, but the second, much, much smaller moon, Selene, actually orbits Luna. Selene ...
10
votes
4answers
241 views

A brighter moon that's harder to see

In honour of the full moon an odd moon question for you all. The idea is to create a situation in which the inhabitants of a world believe utterly that the moon only exists at night. I'd also like to ...
10
votes
6answers
318 views

Do moons determine the speeds at which tides move? Is there a limit to this speed?

I'm writing a short story that takes place on an imaginary planet that is 88% ocean. The planet has two moons and one continent that is regularly flooded under 500 to 1500 feet of water. The tides are ...
6
votes
2answers
151 views

Multiple moons but only one of them is tidally locked to its planet?

A habitable planet with multiple moons, only one of which is tidally locked to the planet: is this general scenario possible? I understand that tidal locking takes a very long time to happen. So ...
5
votes
2answers
110 views

Will be possible in the far future to create an artificial Moon for Earth and terraformed planets?

Will be possible in the far future to use megascale engineering to create an artificial hollow moon to give Earth a big moon in the sky like in billion years ago? Since it would be hollow, it would ...
2
votes
2answers
93 views

Concise, formal way of describing a particular meridian of a moon

Say I have a moon orbiting a planet. Due to tidal locking, if we model the moon as a sphere, there exists an axis which passes through the center of the moon which is always pointed toward the center ...