Questions tagged [planets]
For questions about any large astronomical bodies classified as planets, and their effects on their systems.
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How would a Larger Planet with a Thicker Crust than Earth affect Tectonic Activity
The basics are the planet is larger in both mass and size, but lower in density than the Earth.
In a previous question I asked about methods of reducing said Density which involved thickening the ...
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How deep would a canyon on this planet have to be to have an earth-like atmosphere?
I have, for a while now, been intrigued by the planet Canyon in Larry Niven’s Known Space universe:
Canyon was once an uninhabitable Mars-like world known as Warhead. It
is the second of seven ...
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Climate types for large volcanic islands on tidally locked planet
My planet is tidally locked to a red dwarf, which itself orbits a yellow sun like our own. It has roughly the same atmospheric conditions as Earth (perhaps a slightly thicker atmosphere, but not ...
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Is there a way for a Super-Earth have Earth-like Gravity?
I have a planet about 2 Earth Radii large, and even at a lighter Density this puts it squarely in the 10 Earth Mass Range and about 2.5g. It's about 90% ocean, has a thick atmosphere, and near ...
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How do I get the outer planets to meet in the night sky every 1-2 yrs on my planet?
One of the cultures in my story lives on the dark side of a tidally locked planet. I had an idea that they would mark longer spans of time by the appearance of the three outer planets in the system in ...
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Geological activity and of superearth - cannonball moon system
I understand that this situation is hypothetical -- I just need a piece of advice to make it more realistic.
In my story, there is a superearth of 4,5 Earth masses and 1,35 Earth's radius, rotating ...
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How old must The Moon be?
Some time ago, aliens placed the Moon around Earth with every intent to deceive us about its authenticity, except for the glaring synchronization that allows for total solar eclipses, as something ...
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Colorful desert on a lifeless planet that has water?
The planet has earth-like atmospheric pressure and size, it's in the habitable zone, and has 45% land and 55% water (that absorbed a lot of CO2), with an atmosphere of almost 98% nitrogen and not so ...
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Can the mass of a rocky Super Giant be artificially reduced?
THE PREMISE:
Let's imagine a solar system with at least two rocky planets.
One is Earth sized "A" (or smaller) and the second is a Super Giant "B".
Both are in the habitable zone ...
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How could an iron planet be geologically active?
So I have an iron planet, and its name is Randall.
Since Randall is an iron planet, he is basically the core of a planet with no crust/mantle, and very few silicates. Now, I, the creator outside of ...
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Plausible evolutionary changes for fauna on a terraformed planet?
My planet is a tidally locked rocky planet (90% Earth surface gravity) orbiting an M-type star. This M-type star orbits a G-type star at roughly 1.5AU.
This means that it has a kind of day/night cycle ...
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Distances needed to make this system stable
Let's take the Trappist-1 system, and specifically, I'm thinking about the star itself and Trappist 1e because it's the most habitable of the seven planets:
Trappist 1 star is approximately 8.98% of ...
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Is there enough nitrogen in nitrates on Mars to create a thick atmosphere? [duplicate]
One idea concerning the terraforming Mars involves breaking down nitrates in the regolith, (which the curiosity rover confirms exist) into nitrogen and oxygen/ozone. These gases are key in creating a ...
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Would these solar systems be stable?
I have two solar systems in my world that I'm not sure would be stable. I'm not concerned about whether they could evolve naturally (they didn't), just whether they would be stable if set running.
The ...
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Having a long winter every four years - regularly [duplicate]
I'm in the process of writing my novel (actually I've just about finished the second draft and am due to send it to my editor).
It is a fantasy/sci-fi mix, and every four years the planet experiences ...
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Can I use the Peltier effect to cool down an underground city on Venus
In my fiction I have a city deep underground on the planet of Venus. I know this is deeply impractical, and there are far easier places to build an underground city, but that is not what I have done.
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If possible, what would be the conditions for a planet like Earth to have an emerald green sky in its twilight zone? [closed]
Regardless, how can I get an idea of how the color of starlight, or any other natural phenomenon, impacts the color of the sky at different times of day?
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Would a rogue planet experience more asteroid collisions?
I'm working on a novel where the characters inhabit a rogue planet. Would that planet get hit by more asteroids due to the fact that it isn't orbiting a star? I have a feeling that the distance is ...
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Plausibility of a planetary ocean containing both $H_2O$ and a form of potassium?
To give a bit of context, I'm trying to tackle a challenge I set out for myself in writing up a speculative biosphere wherein complex land life emerges, without the advent of photosynthesis at all. As ...
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Would this unorthodox planet be habitable by carbon based life forms?
While researching volcanoes, it’s very clear super-volcanic eruptions are not only dangerous to life in its vicinity, but the entire planet as it can decrease global temperature and cause long periods ...
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What would a small Death Star look like? [closed]
Most of us know the Death Star from Star Wars - a huge planet like structure built in order to destroy planets (160 km in diameter Google says). Now building something that big seems like an overkill.
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Could this sort of celestial system work?
I am attempting to create a pair of planets, both capable of harboring life. Which happens to also be quite colossal in design. We are talking about 10.13x the size of Earth.
So the system I am ...
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How stable would be partial planetary rings on lagrange points?
Context
There's a comparison to what I'm talking about in a larger scale: Jupiter's got its trojans and greeks, Earth does have them too. Those are more or less loose and sparse groups of asteroids ...
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Would the magnetic fields of double-planets clash? and what would happen then?
I will take the basic properties of a previous post
"To make it easier, assume both planets have same mass, radius, and
atmosphere as Earth, they orbit each other at a very close distance of
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Can someone tell me what a world with a radius 1.2 times that of earth’s would be like? [closed]
I want to make a world larger than earth for a story I want to write. Please can someone tell me about the different characteristics a world with a 20% larger radius would have:
How much gravity it ...
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Could it be possible to have a planet made of chunks of floating rock?
I've had an idea for several unique planets in my sci-fi fantasy world, perhaps the most unique is the capital of the alliance between several interstellar governments. The planet is made of thousands ...
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Help with a planet that resembles Mercury: double sunset/sunrise etc
I'm new. I'm here because I need help for the geography of a fantasy planet I'm building. I don't want to be scientific, but I also want that my planet is credible. I imagined a planet that has maybe ...
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In what detail can you examine a distant planet's atmosphere?
Scenario
We've got a terrestial exoplanet three times the size of Earth, 1800 light years away and with an atmosphere similar in composition to Earth's. It is determined via studies that atmosphere ...
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Thermoelectric-powered electromagnets to render Mars habitable
The answers to my latest question on restarting Mars core have finally convinced me; I have abandoned the concept of doing so. However, whilst morosely browsing other questions on giving Mars a ...
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How safe it would be to look at the other planet in double-planet system with naked eye?
To make it easier, assume both planets have same mass, radius, and atmosphere as Earth, they orbit each other at a very close distance of 30,000km and they are tidally-locked, in that case the other ...
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planet atmospheric composition
I am been making an alien planet for my xenobiology project, this planet would have an atmospheric pressure of 1.5 atm and it would be composed of the following gases:
Nitrogen: 83.7%
Oxygen: 10.4%
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A Grasslands Planet
I was wondering if a planet's main biome could be Grasslands. Such planet can even exist? Is it possible to have a planet who's mostly Grasslands with other biomes being the minority?
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Colour of the sky on a planet near a red dwarf [duplicate]
The twin planets Rhoda and Mary are two planets orbiting Barnard’s Star, a red dwarf star 6 lightyears from earth. The two orbit 0.05 AU from their sun, and 415,000 km from each other. They are ...
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How would climate zones be distributed on a planet with 45 degree axial tilt?
This relates to my previous question about a fictional planet: Length of seasons on a planet with eliptical orbit.
In short summary, it is an oceanic world with many islands and archipelagoes that ...
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Would Liquid CO2 form a Separate Layer Beneath the Ocean?
In the series of stories that I'm writing, I have a star system with one of its outer planets being a world with a thick carbon dioxide atmosphere, similar to venus, but it's far enough out to be room ...
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Would humans on disparate planets with little to no contact with one another continue to evolve along different lines?
Would humans on disparate planets with little to no contact with one another continue to evolve along different lines?
In this universe, humans left Earth a hundred thousand years before. Or if it ...
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Scientifically plausible alien species: skin pigmentation
What variables (in a hypotetical alien planet) can lead an underground alien species to have red skin pigmentation? I was thinking of widespread presence of pervasive ferrous compounds in the ...
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Would a breathable atmosphere be possible on an ice planet?
For my setting, I want to create an ice planet composed primarily of water, containing a subsurface ocean. It would be roughly the mass of Earth. As cybernetic/genetic modification is prevalent in ...
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Can a rocky planet form between gas giants?
The Question
I am working on filling in the planets of the Ilus system. I am setting up a strange, huge, low density, sort of habitable world in the gap between two gas giants. Is there a way for a ...
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How long would it take to run out of “space” in storytelling for an average sized galaxy? [closed]
I know that the average galaxy has over 400 billion stars and most stars have planets around it so it seems foolish to think the writers would ever run out of planets. It’s just for the suspension of ...
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How to estimate the energy output of artificial suns
Setting
I'm designing a world where only a thin belt wrapping the equator of a planet is hospitable. It would look something like this:
The backstory, diluted for brevity, is that the central sun was ...
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How to build a gas giant?
In this universe, gravity wells are needed to enter and exit FTL, many cheap spacecraft are not armored enough to go near a star so gas giants are the next best option.
One particular solar system has ...
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Creating a second earth: How to make a continent?
So, to cut a long story short, a group of people are attempting to turn an earth-sized exoplanet into a new earth; that is, a planet artificially made indistinguishable from old earth.
This planet has ...
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Could a planet have 1/2 the Earth’s mass but 1 g surface gravity?
So, we have a captured planet/moon orbiting a gas giant in the habitable zone. It is akin to prehistoric Mars, its geological activity having been maintained by constant tidal flexing from the gas ...
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I’m trying to imagine an Earth-like planet around Barnard’s star
What I have established about this planet is that it is the size of Earth but it is located 2.2 AU from Barnard’s star, a red dwarf. I’m trying to figure out how much greenhouse gases are needed to ...
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What is the minimum specifications for a ship to survive propulsive reentry?
Backdrop
In the ending of my book, the closing scene is the control room of the mangled and torn-up starship diving into the atmosphere (maybe not so dramatic) on its fusion engines, slowing down and ...
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White-hot tungsten moon emitting heat and light to make my world habitable
Never mind how the tungsten sphere formed. That's part of my pet projects, and I will deal with the question of how a nearly pure sphere of tungsten the diameter of the moon formed in space later.
So, ...
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Using solar sails to accelerate a planet’s rotation [closed]
So, just pondering on methods of terraforming venus, it seems that the first step regardless of what comes is to speed up its rotation. This will strengthen its magnetic field, not to mention cool off ...
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What would humans look like on a tidally locked moon with 0.7 G, 0.85 atm of pressure and at the distance similar to mars? (more info in the picture) [closed]
In the picture is the info box of the tidally locked moon of Vaskas. I'm working on a nation what lives on this moon but I would like to know how people on this moon would look like. (This is my first ...
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How would giant creatures that "live" underground shifting their limbs affect seismic activity
Please excuse me if I make any mistakes, this is my first post here.
If there were giant creatures, ranging anywhere from 20,000 square miles (approx. 30,100 square km) to 100,000 square miles (approx....
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