Questions tagged [orbital-mechanics]
For questions dealing with how bodies interact with each other in space via gravitation.
3
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3answers
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A planet that cannot be orbited [duplicate]
I'm wondering if it is possible for a planet to be impossible to orbit stably over a significant length of time. The shorter the length of time the planet can be orbited for, the better. It should ...
6
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3answers
403 views
Practicality Of Orbital Fusion Reactors for Power
Much of the struggle with terrestrial fusion power seems to be with keeping the ultra-hot plasma contained. In a classic Tokamak configuration, magnets using massive amounts of power, suspend the ...
8
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2answers
332 views
Harvesting resources from a geostationary point 100km above sea level
Consider a planet which is entirely Earth-like. Same mass, same rotation, etc. But in this world, resource-rich objects are suspended by some phenomenon at varying altitudes up to 200km above sea ...
7
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1answer
73 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 ...
2
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1answer
96 views
Earth tilt changes due to space launches
How many rocket launches are needed to change the axial tilt of the Earth so much that it is noticeable with instruments available today?
We can assume that we are talking about the heaviest rocket ...
2
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2answers
105 views
Artificial satellite in a Binary Star System
Is it possible for an artificial satellite (in this case, an unmanned communications platform) to maintain a stable orbit directly around the barycenter of a Binary Star system, as in well inside the ...
7
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3answers
293 views
Let's plot a course between Earth and Gor
We know that Gor, or Counter-Earth, is not stable in a long-term sense. Let's handwave that away, or assume that we are dealing with a temporary span of time in which the instability is immaterial.
...
0
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1answer
81 views
Semi-Brachistochrone, Is It Possible?
Would it be possible for there to be an almost torchship (essentially a very, very weak one) which could fly almost brachistochrone trajectories? So instead of a full on brachistochrone, where you ...
6
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5answers
637 views
How likely is the flotsam of a space battle to be captured by our sun's gravity well?
A light-year distant from Sol saw the collision of a massive space-born battle fleet against an awe-inspiring dreadnought. At one point in the battle, the flotilla fired rail-guns with 100 metric ton ...
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2answers
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What sort of acceleration would I need for my space ship to reach Eris in 3 months
I have been working on a sci-fi story for a little while now, and have recently discovered that I made a very big error in assuming the position of Eris. The main issue is that I had forgotten to take ...
8
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4answers
3k views
Rings made out of water? [duplicate]
There have been numerous questions on this site about moons being composed entirely of water. However, is it possible for a planet to have rings made out of water?
I think that the ring would ...
7
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2answers
164 views
Can I arrange my stars in a tetrahedron?
Inspired by this question:
Consider a trinary star system, in which the three stars are arranged in an xy plane and all revolving the same direction, equidistant from each other. The inward pull of ...
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5answers
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Are there any software tools available to map the solar system hundreds of years from now?
I am writing a scifi novel based roughly four hundred years from now, and it occurred to me that the planets and other objects might not be quite where I need them to be for certain travel details to ...
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9answers
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Would it be more efficient to build fleets in orbit?
My Dino theme park business didn't end well and I reluctantly fall into depression and decided to go into suspended animation to seek a cure. 200 years later, a lady claims she works with the military ...
13
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4answers
2k views
Could the moon crash into the earth if we colonised it and increased its mass?
Suppose we begin to colonize the moon. Assuming the building materials and biological material are all imported (not taken on-site), would it be possible for the moon to become massive enough to fall ...
9
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2answers
301 views
A supermassive black hole is coming our way. When's the latest that we would notice?
I'm trying to build a story around a supermassive black hole, which is ejected from a merger of two galaxies, that is hurtling our own way. What is the smallest realistic distance at which the black ...
4
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2answers
111 views
Getting Three Comets to Synchronize Their Orbits… Occasionally
I'm working on a flintlock fantasy series and I want to figure out how to get three comets with different orbital periods to occasionally all show up at the same time. All three are "great comets" ...
1
vote
1answer
111 views
The dreaded apocalyptic asteroid approaches Earth but lands 'safely' on the Moon [closed]
NOTE- PLEASE DON'T ANSWER HERE. I'M DELETING HERE AND MOVING TO SPACE EXPLORATION SE. https://space.stackexchange.com/questions/32411/the-dreaded-apocalyptic-asteroid-approaches-earth-but-lands-...
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8answers
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Why would it be unfortunate for a day length to vary in a planet; other than that Java API developers need to work a few hours more? [closed]
Quoting from the Java Docs:
Unfortunately, as the Earth rotates the length of the day varies. In
addition, over time the average length of the day is getting longer as
the Earth slows.
I am ...
6
votes
2answers
655 views
Habitable zone around a Blue Supergiant
I am writing a story centered around a planet orbiting a Blue Supergiant star.
What I want to know is how far away a planet would have to be to be in the habitable zone of such a star. The star I ...
4
votes
2answers
152 views
What would be the impact on Titan, Saturn and the Solar system if aliens harvested as much hydrocarbons as possible from Saturn's moon?
The scenario
Many science fiction novels are concerned with aliens visiting Earth, but what if aliens have no interest in Earth at all and yet they arrive at the Solar system for the sole purpose of ...
0
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1answer
69 views
Temperature on a bulls-eye planet planet orbiting a red dwarf star [closed]
I recently attended a talk on current research into exoplanets and it got me thinking. I want to create a setting on a tidally locked eyeball planet for a futuristic sci-fi story.
What I want to ...
3
votes
1answer
96 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. ...
1
vote
1answer
93 views
What kind of impact could strip Venus and make it spin faster?
I'm trying to create plausible scenario under which we could colonize Venus.
Is it possible that Venus could be hit by a planetoid and the impact strips its atmosphere and makes it spin faster?
I'm ...
2
votes
2answers
132 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
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1answer
100 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 ...
8
votes
3answers
323 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 ...
3
votes
2answers
57 views
Opaque Solar Shield in Geosynchronous Orbit: Plausibility + Challenges of Maintaining Orbit
Suppose humans of the late 21st century or beyond began constructing a solar shield as a solution to climate change. Suppose for some reason (open to suggestions) they choose to build the shield in ...
25
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14answers
8k views
How do you non-catastrophically reduce the mass of the Sun by half?
In my previous question, I asked how much mass the Sun would have to lose in order for Saturn's orbital velocity to be its escape velocity.
The answer proved to be somewhat unexpected - when the Sun ...
13
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4answers
1k views
Can the Sun lose enough mass that Saturn's current velocity becomes escape velocity?
Imagine that, through some cosmic phenomena not yet understood, the Sun 'burps' and ejects a vast amount of its mass into the cosmic void. A huge coronal discharge, perhaps. A pressure bubble inside ...
1
vote
1answer
131 views
Two planets with the same orbital period [duplicate]
I have the following star system configuration:
All bodies always stay on one line.
Star is similar to sun by parameters.
"Green" planet is Earth-like exoplanet with 1 earth-year orbital period, ...
4
votes
1answer
169 views
What impact would a giant alien spaceship orbiting Earth have on our planet? [duplicate]
I'm talking about a massive ship, let's say half the mass of the Moon, within the Hill sphere, so that is not snatched up by the Sun and can orbit around Earth.
Assuming it's positioned as far as ...
13
votes
1answer
270 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). ...
20
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1answer
1k views
Could a planet's Karman line hypothetically occur under a liquid surface?
The Karman Line is one of the most commonly-used definitions of the "edge of space". As an airplane flies higher in the atmosphere, the air gets thinner and thus the lift decreases. This can be ...
1
vote
1answer
174 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
174 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 ...
4
votes
5answers
199 views
A planetary region with no night and no tidal locking?
Without tidal locking, would it be possible to have a planet with a region roughly the shape and size of the USA and Canada in which it is always "day"? (By day I mean at least as bright as a clear ...
4
votes
1answer
168 views
Would this simplex ternary system be stable?
I'm trying to make a trinary star system but I'm not sure how it would work. The primary star is an M0Ve star (red dwarf flare star). The orbits of the other two stars are slightly more complicated. ...
2
votes
3answers
256 views
A cure for the 'Kessler Syndrome'? [duplicate]
For those unaware, the term 'Kessler Syndrome' refers to a scenario in which space-borne debris reaches a 'critical mass', destroying spaceborne satellites which in turn produce more debris which in ...
49
votes
14answers
9k views
Can I produce a true 3D orbit?
I've been doing a little research (including reading Howard Curtis' Orbital Mechanics for Engineering Students) because I want to build a solar system with a planet that has a true three-dimensional ...
2
votes
3answers
138 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 ...
6
votes
2answers
192 views
How feasible is my Exo Planet - Penumbra
My planet - let's call it Penumbra for now - exists at roughly 1.5 AU from it's sun - which was similar to Earth's - but is about a billion years older.
It is 15% more massive than Earth, but nearly ...
3
votes
1answer
79 views
Would there be stress on my wormhole between two planetary surfaces due to their orbits?
Building on this question: Settings formed by Uncontrolled Terraforming of Venus and Mars via Portals
My government, the Great Council of Duhurang1 has authorized the Minister of Astronomic Science2 ...
3
votes
2answers
135 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 ...
6
votes
2answers
155 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 ...
7
votes
3answers
408 views
Navigation on a tidally locked planet
I have a tidally locked planet on a circular orbit, with an axial tilt of 22.5°
That means one side is always in the sun, the other one in the shade. The subsolar point moves along a north-south line ...
9
votes
1answer
220 views
The Nightfall / Kalgash System
"Nightfall" by Isaac Asimov (you can hear the story here on escapepod, if you need it) postulates a planet in a multi-sun system. The orbital mechanics of the 6 suns result in all of the sides of the ...
2
votes
2answers
223 views
How many habitable planets can I fit into the habitable zone of a Sun-like star and still be stable? [duplicate]
The habitable planets will be very similar in size to earth and are on separate orbits orbiting a Sun-like star exactly the size of our own Sun. How many habitable planets can I fit into the habitable ...
3
votes
1answer
139 views
How long can a moon remain non-spherical, and what might it look like when full?
I'm trying to "build" a world in which the moon is always visible at night, and only at night, to the majority of areas on that world. I've been told that an L2 Legrange point could be a viable ...
4
votes
1answer
126 views
Describing a planet on a comet like orbit
I have a planet in earth's solar system that is on a comet's orbit rather than like the orbits of the planets we have. I need some help picturing how this would work to meet a few requirements for the ...
