Questions tagged [planets]
For questions about any large astronomical bodies classified as planets, and their effects on their systems.
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(Fixed) Fictional calendar is 345 days with 28 hours per day and 14 hours day and night cycle--how old are 13 year olds vs Earth calendar? [closed]
I had the worst brain fart earlier, sorry.
My fictional calendar is currently 345 days with 28 hours per day, with 14 hours day and night cycle [I have no idea why I effed that up so badly prior]. I ...
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Experiencing a planetary near-miss [closed]
I enjoyed this post discussing the collision of two planets. Everyone dies of course. So I'm wondering how close can two planets get, and still leave most people alive. E.g. a Mars-sized planet ...
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What's the maximum mass for an Iron Planet to have a magnetosphere like Mercury's?
I'm designing an iron planet which migrated into its habitable zone. Basic research told me iron planets cool off too quickly to have a magnetic field, so initially I was looking for ways native life ...
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Could Moon Phases work in a Concave Hollow-Earth?
I'm trying to wrap my head around how phases of the moon(s) would operate in a hollow earth. For reference, I am picturing a situation like this:
In this system, the center of the hollow earth has a ...
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What would a rough estimate of the global climate of an earth be like if lit by a geosynchronous ring instead of a point source?
Welcome to fantasy earth: like Earth in all the same ways, with the exception that the sun you know has been replaced with a ring you don't.
What would the climate of Earth be if the sun was replaced ...
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How would a planet's surface be younger than the planet itself? [closed]
Europa, one of Jupiter's moons, is 4.5 billion years old (like Earth.) However, its surface is only 20-180 million years old. What could lead to a planet/moon's surface being younger than the planet/...
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How can an Earth-like planet support two moons of different sizes [closed]
In my world, I need to have two moons orbiting an Earth-like planet. I need the extreme tides as they play a big part for a cultural detail. The first moon should be roughly the size of our own moon, ...
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What composition of atmosphere would work with CO2 best? [closed]
I'm working on a solar system where there is a planet with a red-ish atmosphere, due to it mainly being composed of CO2. I know CO2 doesn't react with many chemicals and is pretty dull, molecule-wise. ...
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Could this hypothetical Super-Earth support human life?
The Question Could this hypothetical Super-Earth (Planet Y) support the lives of human settlers arriving from off world, or have I created any reasons for the planet to be inhospitable?
Planet Y
Star: ...
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How much difference would Alpha Centauri A cause to the climate of a planet about Alpha Centauri B?
Imagine an earthlike planet in the habitable zone of Alpha Centauri B. Call it ACBc (although I am not sure ACBb has been confirmed). When ACA and ACB are closest to one another, they are about 11 AU ...
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Could this hypothetical Sub-Earth support human life?
The Question
Is a theoretical 2/3rds - 7/10ths Earth big enough to have the magnetic field, atmosphere and plate tectonics to do this, or will I wind up geologically killing the planet?
I have been ...
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What astronomical situation could account for the PERCEPTION of a very erratic day / night cycle for a planetbound population with limited science?
I would like to create a world that is at a roughly medieval level of scientific understanding and which - as far as it appears to the inhabitants of that world - has a highly erratic day and night ...
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How would weather work on a planet with no rotation and constant sun on all sides?
A while ago I had an idea of a man made planet that consist of a thick, incredibly strong, outer crust, and at the core there is an antigravity/antimatter device that also produces consistent heat and ...
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Could a planet realistically share an orbit with Jupiter?
So I've been working on a project where I modify the Solar System, and I originally had a small gas planet(like 5-10 earth massses) named Juno orbiting between Jupiter and Saturn. However, as it turns ...
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What could lead a large ocean on a planet's surface to recede completely only to reappear later on in a cyclical process?
I don't just mean tides or large-scale floods and droughts but a premise where one or more large bodies of water (or even every such body if that makes it easier) disappear, only to reappear one or ...
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Auroras of a planet around an active M7 red dwarf
A planet the size of earth around a pretty active M7 red dwarf (think of M to X level flares almost every day) has a decent magnetic field of 0.5-0.8 Gauss, orbiting at a distance of 0.0443AU, with a ...
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Is my planet's atmosphere livable for humans?
My planet has a atmospheric pressure of 1.4 atm. The gases that make up the atmosphere are 79% nitrogen, 18.6% oxygen, 1.4% argon, 0.5% water vapor, 0.3% xenon, 0.02% CO2, 0.01% krypton, 0.17% other ...
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What is the lowest reasonable density for a Super Earth with earthlike living conditions?
A large planet roughly 3-4 times the mass of Earth. Trying to keep Gravity between 0.75G-1.25G for Earth-like Conditions.
I've looked into certain materials such as Silicon Carbide, which is ...
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Plausibility of life emerging and evolving on gas giant moons?
I have been working on the setting for a hard speculative biology/evolution project that for now will simply be referred to as the Gemini Project, and the main issue I've been having is whether or not ...
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Plausibility check for a planet
I have a question about the plausibility of this planet.
2.696246 Earth Masses
1.5 Earth Radii
1.2g
4.4044746136 g/cm3 (0.799 Earth's)
I know that the density falls within a range for a terrestrial ...
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Could a planet orbiting a g type main sequence star have yellow on its surface? [duplicate]
I had saw somewhere that a habitable planet orbiting a g type star same as our own could have yellow plants so could it?
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Could a planet 2 times the mass of earth have floating organisms in its skies
Can a planet 2 times the mass of earth have floating animals in its skys? I watched the netflix documentary series ailen world's and one of the exoplanets atlas was high gravity but was very dense so ...
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An ocean-planet made out of deadly, non-water chemicals
I'm currently working on a comic-series set in a solar-system that isn't ours, and i'm reworking most of my planets.
One of them, a cold ocean-planet below freezing temperatures that orbits its k-...
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Could humans live on a cylindrical celestial body?
Let's imagine a roughly (or perfectly?) cylindrical celestial body. Other than it's shape, everything about it astronomically (distance from sun, orbit shape, etc.) is the same as Earth. Is it ...
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Could humanoid life survive the violent formation of a planetary ring system?
The deepest mythological archetypes in my Earth-like world hint at a wondrous and terrible disaster in the ancient past. ~10 tya a celestial body (perhaps a small, second moon, or a wandering asteroid,...
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An atmosphere that gets denser with increasing altitude, to support these flying creatures
I'm thinking about implementing a race of flying creatures in my current setting: an earth-like planet with a breathable (enough) atmosphere. The easiest way to do this is just creating a race of bird-...
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Can there be habitable moons despite heavy changes in axial tilt of their mother body?
Ok so i created a gas giant with 10 Jupiter masses and like 9 moons between 0.8 and 1.5 earth masses. All exept the most distanced of those moons are tidally locked to the gas giant and their axial ...
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What would a planet where giant creatures live be like? (gravity, weather, etc.)
I am thinking about a planet on which gorilla-like people live in. Gorilla-shaped, walking on their knuckles, but with the capability of complex speech and a slightly more humanoid face (possessing a ...
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Is this ocean-planet stable?
I'm building a cold, water-based ocean-planet for my current setting, its temperature being below 0°c at all times and in all of its regions. Even despite the freezing temperatures, the planet's ...
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How possible is a habitable, liquid ocean-planet at temperatures below 0°C?
I plan on having an ocean-planet with a breathable atmosphere built into my current setting, orbiting its host-star (a K4v main-sequence star) a short distance beyond its frost-line, with oceans that ...
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Continent Formation and Volcanos
For over a year I've been writing about a fictional race of people that has taken on rather a life of its own. They live on an earth like world with similar geological processes to our own but I don't ...
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How to make a hybrid mapping system for aircraft on barren planets without celestial or compass use?
My captains and pirates belt out lots of navigational commands and jargon, but none of it can relate to terrestrial maps. So I’m needing a system they use in transit and combat, that they will ...
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Is it possible to store the gravitational energy between planets somewhere in space? [closed]
Say I have a space station operating between Mars and earth. Can it somehow steal energy from
Mars- Earth
Earth - Sun
Sun - Mars
Combinations of gravitational pulls?
Would it distort he orbits?
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Could a captured planet end up in the habitable zone of a new star system?
Is it possible for a planet to be ejected from one star system and end up in the habitable zone of another? Or do captured planets always end up in wide, eccentric orbits?
I guess in the vast expanse ...
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Can a tidally locked planet with two counter-orbit moons exist for at least 100,000 years?
I believe it is true (correct me if I'm wrong) that a planet with a significant moon such as ours cannot be tidally locked. The orbit of the moon would continue the rotation of the planet and must, ...
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How might planet size affect volcanic activity?
I'm working on a project involving the evolution of life on different hypothetical habitable planets. In imagining different atmospheres on planets of different masses, I'm wondering how a planet's ...
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How stable would a rogue star system be?
By some means, artificial or naturally occuring, a human inhabited star system has been flung from the Milky Way. Prior to being ejected from the galaxy, the system bears at least one Earth-like ...
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Could a planet orbiting a star have a habitable moon and this moon have its own moon orbiting it?
Could a star system exist where a body orbiting the star has an inhabited planet moon orbiting it instead of the sun? And the inhabited planet moon has its own smaller satellite.
I have very little ...
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What would happen to an Earth-like planet if it had a more magnetically permeable inner core?
I was contemplating the impact of doping an Earth-like planet's core with a substance that alters its magnetic permeability. Specifically, I considered a scenario where the planet has an improved ...
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How far from a habitable planet must a red giant star be to not seriously affect it?
Can a habitable planet having complex life exist in a binary star system with a Red Giant? I am not talking about close binaries, but distant binaries (100 AU or more). Planets can orbit some smaller ...
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Tides on an Inhabitable planet with rings
I've occasionally pondered the notion of an inhabited planet similar to Earth in terms of size, gravity, atmosphere etc., but with rings circling around it an a similar manner to Saturn. One question- ...
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Would the substellar point on a tidally locked planet with a large continent over that point and oceans around the edges be covered in rainforest?
I have been working on a tidally locked planet for some time now. During this time I have worked under the assumption that the substellar point would be arid because of the constant bombardment of ...
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Behavior of narrow straits between oceans
I am trying to build a world that would have two oceans separated by a narrow sea/strait/passage.
Think of Drake's Passage, but bordered by large land masses from both north and south, like the ...
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A 1:1 tidally locked world begins to spin. What sorts of non-solar natural disasters occur?
As stated a tidally locked world that has complete 1:1 begins to spin slowly. It starts slowly, a 2:1 ratio that steadily ramps up over the course of a month to one rotation every month, which would ...
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Plausibility, habitability and conditions of shell-system
I have some questions regarding the feasibility of this planetary shell-based construction. I have read other questions about shell worlds, but this case has some unique elements, so I thought I would ...
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Could earth like planet support a second moon, if it was approximately 1/4 of real moon size?
I would like for my world to have two moons. I think it would look simply stunning at night. Also, I came up with a pretty cool idea for a "God Eye" cult. When the smaller moon would have ...
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Is it realistic to have 7 months in a year?
I'm aware of the property of the number $2520$. It's divisible by all integer numbers from $1$ to $10$.
One of the factorizations of $2520$ is $7×360$.
It came to my mind to make a habitable planet ...
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Looking for a Specific Planet
I know my title isn't the most specific, but the planet I am looking for is. I have been looking through many exoplanets and I can't seem to find what I am looking for, the closest I have found is ...
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Decaying Planets
Assume there is this planet with only one type of life; a planet-wide mat of microscopic lithotrophs. These creatures eat through the surface of the planet over time, converting the surface into gas. ...
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Is it possible for polar nights at one pole to be 8 & 1/2 months long without significantly messing up the climate?
Is it possible for polar nights at one pole to be 8 & 1/2 months long without significantly messing up the climate?
The length of polar nights at the south pole from what i know is a week longer ...
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