All Questions
Tagged with exoplanets or planets
2,759 questions
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How would a planet with 12 luna sized moons work, orbitally speaking?
I have a planet around 0.8x the size of earth(in terms of volume, but with a higher density to maintain the same level of gravity.) orbited by 12 luna like moons (sameish density, samish size). These ...
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6
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934
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If a nuclear war occured on Earth, what evidence could a Martian astronaut see?
An astronaut is alone on Mars when, unbeknownst to her, a total nuclear war breaks out on Earth. Other than Houston being unresponsive, is there anything she can do to establish what happened on Earth?...
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3
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What is the largest distance at which a Cube-world is distinguishable from a spherical world?
A Cubeworld and Cubemoon with uniform surface gravity have been engineered using materials of arbitrary strength and density, the cubeworld made habitable, and placed into orbit around a star. The ...
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Terrestrial planet with rings has occasional meteor showers that cover much of the habitable space, what would the native species do to survive them?
One of the most important planets in my story's world is Australis, a habitable terrestrial planet with rings and a single moon. The rings contain a valuable metal ore which is mined to be used as a ...
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Building a planetary system: realistic orbits, with regard to dynamical evolution
I'm attempting to nail down concrete details of a planetary system I've been working on. Working from the top down, I think it's necessary to determine orbital characteristics of the planets first.
...
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63
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Is it possible to increase the size of the Earth and still retain liveable circumstances for humanity on its surface? [closed]
I am concepting a science fiction thriller called Super Size Earth where in a distant future humanity tries to solve the problem of missing space via increasing the size of the earth. I am imagining a ...
Pontigoner Racing
4
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5
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1k
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Planet with minimal atmosphere and solid surface
I know it's not possible to have liquid exposed to vacuum without freezing or vaporizing.
Talking about a planet, with similar gravity to that of Earth, with no land emerging from an all-encompassing ...
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4
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if a rock (like 6.4 cm or 2.5 inches) had gravity that was comparable to a planet or other large-ish astral body?
for context I have a character who's basically an earthbender but they can alter the gravity of the earth they manipulate. What would this do if it was, for example, used as a projectile. Yes there is ...
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1
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161
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Would this "Wet Venus" in my timeline be possible?
I want to include an "Wet Venus" planet which will have both terran and venusian aspects in a major planetary system which exists in my timeline, though i've been wondering: Would it be ...
user119110
9
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6
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How might communications on Mars work between bases if humans were there?
How might communications on Mars work between bases if humans were there? For example if there were humans on bases at the equator and the poles, would real time communication be possible? What ...
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How long would an eclipse last on an Earth-like moon [duplicate]
I’m creating an earth-like moon that orbits a gas giant planet the size of Jupiter. The planet orbits its star at the same distance mars orbits the sun and it takes the moon 295 days to orbit its ...
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0
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17
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how would I calculate the greenhouse effect based on the atmospheric composition [duplicate]
So say I have a planet that has an atmosphere of 1 atm, and is 78% N2, 20.16% CO2 0.84% O2 and 1% Ar, and it orbits a star that is about 40% as bright as the sun, the planet orbits at a distance of 0....
4
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1
answer
125
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How would tides work on a habitable moon orbiting a gas giant?
Lets say, there is a habitable Earth-like moon orbiting around a gas giant, which orbits around an F-type star. The gas giant is slightly smaller than Jupiter, and the moon is slightly smaller than ...
4
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1
answer
138
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How would a Hot Jupiter work in a P-Type Binary System?
This is my first time using the board so sorry for any mistakes.
I am currently designing a stellar System for my fantasy world. It is a P-Type Binary system which I have based upon a modified Keplar-...
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3
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1
answer
88
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Tilt of the rotation axis around the barycenter in a binary planet
In the previous question I was told that in order for the double planet system not to have eclipses every day, their rotation axis tilt around the barycenter of mass must not be 90 degrees.
Both ...
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2
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Is this solar system mechanically possible?
Say, hypothetically, you have two terrestrial planets (b,c), one gas dwarf(d), and one gas giant(e) all orbit the habitable zone in some manner.
b, c, and d all have an orbital resonance, which cause ...
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4
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What effect will a planet’s narcotic atmosphere have on sound of music at rave parties?
I have a tropical (higher average temperature and smaller, more evenly-distributed continents) habitable (for humans) planet. Apart from one thing: it has the following atmosphere:
I still want ...
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5
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1
answer
568
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How large can a network of underground tunnels be before it collapses on itself?
How large can a network of underground tunnels be before it collapses on itself?
In my world I have an alien planet where most intelligent life lives underground in a global network of tunnels. These ...
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10
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5k
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How to make a soundless world
I have an Earth-like planet where no sound can be propagated. Sound mediums are present like air and living beings exist to hear it but sounds are still muted.
Is there any possible way my planet can ...
- 3,357
4
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3
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186
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Getting a planet to be as volcanic as Io
Just to clarify, I am not looking for a magma ocean planet (I already have one in my system interior to this planet’s orbit, at 0.0197 AU from the star, which has a supercritical atmosphere and a ...
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11
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5
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What would a planet need for rain drops to trigger explosions upon making contact with the ground?
The rain of my planet, for some reason, triggers explosions upon making contact with the ground. However, only rain water specifically causes this. Bodies of water like rivers or oceans don't cause ...
- 3,357
3
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1
answer
183
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If Io were the size of Earth, what would its atmosphere consist of?
I am designing a volcanic Hell-like super-Io in my solar system and I want it to be like Io.
Io in real life is, of course, a moon of Jupiter. It has a mass of just 0.015 Earths and has a very thin, ...
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5
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2
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244
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What size should my inside-out planets be so that people on the surface can see the curvature?
The universe is filled with a fluid, and people live on the inside surface of planets. I want planets to be roughly Earth-size or larger (maybe up to 3x), but I want to make sure people on the surface ...
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3
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1
answer
148
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Could you please check my calculation for a habitable binary planet system?
Good day!
For the story I have prepared information about the binary planet system.
The action will take place on the smaller (minor) of the two planets, which is supposed to be habitable.
The ...
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6
answers
1k
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Plausible orbit to have a visible object slowly circle over the night sky
I want to have the inhabitants of a particular world - doesn't have to be a planet, can be a moon - be able to see a certain point of light - can be a planet, moon, star, whatever - moving in the sky ...
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2
votes
4
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142
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Coral Islands and Atolls on a Drip-and-Plume world
I have a world which has a drip-and-plume tectonics, meaning that there are no plate divisions. Instead, plumes of magma rise to the surface to create more scattered volcanism, coronae and gradually ...
- 1,347
3
votes
1
answer
369
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Creating a prison on the high-pressure ice of a deep oceanic planet
I have a superoceanic (H2O) planet ~9.1x Earth’s mass and ~2.1x Earth’s radius. It is a superoceanic planet, meaning the planet is 100% covered in a global ocean 100s of kilometres deep; so deep that ...
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1
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Weather in The Cluster World
Based on Slarty and Robert Rapplean's answers and comments concerning The Cluster World I'm seeing a far more active world than I originally envisioned, some short notes follow.
Atmospheric retention ...
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3
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What unique phenomena would be observed in a system around a hypervelocity star?
A star is ejected at a high velocity from the Milky Way Galaxy, going towards Andromeda at a significant speed. Around said star is a stable planet - that either at the time of ejection or is made to ...
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5
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Is it possible to have a planet that's gaslike in some areas and rocky in others?
Specifically if a planet is an oblate spheroid with a large enough bulge at the equator, could the higher gravity areas hold onto hydrogen and helium, resulting in there not really being a "...
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1
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0
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149
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Astro-Mechanics: Plausibility check for binary system merge
I have a binary system composed primary about a brown dwarf and a k6.6V star that's the fusion of the system 1 and 2 7.41 billion years ago, I'll tell you the story and I'll ask the question after the ...
2
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3
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415
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Could a mini-Neptune host life at the surface with gas giant-style storms up above?
Say there is a planet in the range of minineptune/super earth, with a large rocky surface and hydrogen and helium in its atmosphere, which rises upwards, while oxygen remains closer to the ground. ...
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9
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4
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Will fire still burn well in my atmosphere?: concentration vs partial pressure
I recently learned from this article that flammability in oxygenated environments is far more dependent on the concentration of the Oxygen in the air rather than the partial pressure of the Oxygen.
In ...
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1
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How long would it take for an Earth-like planet to become uninhabitable if another sun suddenly appeared? [closed]
Context: this event is set in a world that I am going to call Earth-like enough. The only important distinction about this planet is that there is a cluster of floating islands held aloft by ancient ...
user115728
2
votes
2
answers
71
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Behaviour of volcanic eruptions and lava under a high-pressure supercritical water atmosphere
Planet with cloud cover
Same planet but showing surface
I have a planet that has undergone a massive runaway greenhouse effect and is currently completing the evaporation phase (it will later go ...
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4
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3
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303
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Habitable world with abnormally low Argon
I want to create a habitable earth-like world (water oceans etc) that is very scarce in Argon (only 4.37ppm of the atmosphere). Two of the easiest explanations for this are:
The world is very young, ...
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11
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4
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Do temperature variations make trains on Mars impractical?
Train tracks are expected to cope with a variety of temperatures. They expand and contract over time and seasonal temperatures.
The Martian surface is subject to significantly more temperature ...
- 1,801
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8
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Venus’ LIP period starts today, can we save the Venusians?
Following this question, let us propose instead that Venus stayed habitable for longer, and a sapient human-like civilisation arose around the same time as our own (and developed technology at a ...
- 1,347
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6
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If Venus had a sapient civilisation similar to our own prior to global resurfacing, would we know it?
Let’s assume that Venus was habitable and Earth-like up until 700 million years ago, when a catastrophic global resurfacing destroyed everything and led to a runaway greenhouse effect, which ...
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Will The Cluster World hold onto an atmosphere for a useful length of time without further intervention?
The scenario goes something like this; a mage pins an earthlike planet's worth of mass (~5.972x1024kg), in the form of rocky asteroids ranging in size from a hundred or so metres to several kilometres ...
- 51k
2
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1
answer
488
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The possibility and effects of xenon in the atmosphere
I'm building a exoplanet with no humans included to do speculative biology, so I'm wondering what kind of effects would xenon have on the planet. I was thinking about a mixture of: N2-72% O2-22.9% Ar-...
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2
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Could there be a sulfuric acid fluid cycle on a colder Venus analogue?
For Venus, as it is, sulfuric acid in the clouds cannot reach the surface as it would evaporate before it does so.
If instead, we have a Venus like planet further out in the habitable zone, we can ...
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14
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What would a planet need to have a sustained blood-based water cycle?
To keep it short, I have a planet with oceans of pure blood. It also 'rains' blood. Because of the planet, a blood-based water cycle consequently forms.
I'm aware that blood is far too viscous for ...
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3
votes
3
answers
359
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Biology of a Planet Sized Lifeform [closed]
This is also part of the sci-fi thing I'm working on, a planet sized lifeform.
The planet sized biological creature belongs to the "Ancestral Elves" species, and is also the capital planet ...
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2
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1
answer
95
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Two Moons Impacts On Day Length and Solar Eclipse?
(Edit: Ive decided against the idea after a conversation with a friend who knows a lot more about astrophysics, thanks for the help tho :) )
As much as I love making ecosystems on exoplanets, I cant ...
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8
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3k
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How can life which cannot live on the surface of a planet naturally reach the supermajority of the planet's caves?
I want to create a setting focusing on a planet where nearly all complex macroscopic life lives underground, but I keep running into a problem: If a complex organism is adapted to cave life to such a ...
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3
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508
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Mars paraterraforming (worldhouse) vs. full terraforming
Ok I had a thought I wasn't sure how to figure it out. If you enclosed Mars in a worldhouse (ie. planetary shell) are there enough volatiles (gases) to make a breathable atmosphere for the whole ...
- 201
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14
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3k
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How can dragons breathe in space?
So, I'm writing about a world consisting of 15+ planets, which revolve around a giant star in the middle of the universe. My question is how I can create a realistic, logical way for dragons to cross ...
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3
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100
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Day-to-Night observable Sky on a Orbital (non-Niven, small ring) [closed]
I'm assuming a lot of things here, but trying to visualize some characteristics regardless. What would the skyline look like? Day/night, seasonally, etc.
I'm imagining a structure that is a ring, but ...
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8
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551
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What evolutionary pressures would lead to massive differences in intelligence between the sexes?
I am writing an alternate history timeline about a habitable Venus. On Venus are two species very similar to humans. They are Machos and Divas; they live on opposite sides of the planet. Both Machos ...
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