Questions tagged [planets]

For questions about any large astronomical bodies classified as planets, and their effects on their systems.

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7
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5answers
263 views

160 Year Solar Orbital Period & 1.9 Year Moon Orbital Period - Is it possible?

A defining factor of my world is the hardships inhabitants have to face when surviving long seasons. Due to the extreme length of a year, time is largely measured by moon cycles. I need to make sure ...
3
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2answers
177 views

Carbon cycle on planet with mainly CO2 atmosphere

What effect would having CO2 in your atmosphere in place of, on earth, Nitrogen have on the carbon cycle? would the carbon cycle even work? I'm engineering A theoretical tidally locked planet with an ...
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1answer
118 views

What would climate be like on a tidally locked planet? [duplicate]

How would climate behave on a tidally locked planet? Would there be zones like the ones on earth or not?
6
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3answers
511 views

How can I get different colours of ocean? [closed]

We think of oceans and large lakes as being blue. How can I get other colours in a way that is reasonably compatible with what we know from terrestial bio-geo-chemistry?
4
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4answers
381 views

Designing the most boring planet ever discovered. Part 1: planetary surface

@Gryphon has made me aware of this The Least Interesting Substance It is very close but I need a planet that can form naturally. Would any of the substances mentioned in answers to that question be ...
4
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4answers
335 views

Is is plausible for an Earth-like planet to have all of its land located in one polar hemisphere?

I made a map for my fictional world and it would be convenient for the story to have all of it affected by a somewhat similar climate. The map is made of several pieces of a Pangaea-like continent ...
1
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2answers
203 views

Properties of a planet roughly four times as big as Earth

I have some research I want to do about a planet for a novel I'm writing. It is a fiction/science fiction novel, but I do wish to actually have some parts of the world correct in the scenes I depict. ...
-2
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2answers
102 views

How would gravity affect a torus-shaped planet? [duplicate]

My planet is a Super Earth about twice the mass of Earth. I'm not asking how it formed, although that would be nice to know. I mostly just want to know how long it would stay a torus shape, and how it ...
3
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2answers
208 views

Terraformed Venus and Mars

A Traveler from a very advanced civilization has visited the Solar system. He found the humans likable, and decided to leave them a boon. For some reason, he couldn't do anything directly to the Earth ...
6
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4answers
288 views

Water planet turns into desert world without being rendered uninhabitable

A habitable (human could survive in its atmosphere without suits) desert planet which used to have large oceans is quite common in ScFi. I was thinking about the processes which could have been ...
46
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13answers
11k views

Can a planet be tidally unlocked?

In my answer to another question, I suggested that the Super-Earth in question be tidally locked to its host star for a period of time while part of its surface experienced a bombardment. After that's ...
15
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8answers
4k views

How to explain one side of Super Earth is smoother than the other side?

A spaceship flew across an unclassified region of the Milky Way galaxy and found a Super Earth in an unnamed system. The planet is almost twice as massive as Earth and is orbiting fairly far away ...
2
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2answers
156 views

How do I figure out temperatures and amount of sunlight for a world?

How do I figure out the temperatures of certain latitudes on a planet with factors such as sunlight and the emission of heat and energy from a planet's interior? Assume the planet is smaller than ...
4
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1answer
95 views

I'm trying to create a planet with a purple sky, human life on planet not necessary [duplicate]

I think that it could be possible with a red sun, and either massive oceans containing algae or a surface covered with active volcanoes. What would my atmosphere be made of, and what color would those ...
3
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5answers
287 views

How can this habitable planet have a moon with a naturally occurring atmosphere?

Assuming the planet is earth-like, with more surface water and atmospheric oxygen, and within the habitable zone of a sun-like star, how can a moon orbiting this planet retain a thick atmosphere? The ...
11
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2answers
2k views

What color should the snow be in this chlorine world?

This question is in the same context (the same world) proposed by Steven L. Gillett in his book: "World-building". And actually there have been some other questions about this same chlorinated world. ...
4
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1answer
229 views

Origin of life on a waterworld

Take a planet like Gliese 1214 B, which has no land, an ocean 100s of kilometres deep and a seabed of Ice VII. For the purposes of the question, let's assume that the pressure and/or temperature near ...
9
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15answers
2k views

What natural phenomenon could lead to greatly varying season lengths? [duplicate]

I'm intrigued by the topos of varying season lengths brought to us in the Game of Thrones universe. I think it makes for a brilliant and versatile backdrop for the story, and it is something I'd like ...
3
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1answer
308 views

Would a planet the size of Mercury with the gravity of Earth be scientifically possible? [duplicate]

I'm trying to do calculations for a planet around the size of Mercury with the gravity of Earth. Would the gravity be too high for a planet this size? Do I have to change some numbers, or is this ...
6
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3answers
158 views

How can I create a new planet/satellite system that generates tides of 6-8 metres?

I'm creating a new setting for a novel. I'd like to build a world where the interaction between the planet and its satellite/satellites can generate a normal tide excursion around 6/8 metres. ...
29
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14answers
6k views

How can I launch a projectile to hit something in orbit, using only geological structures and power sources?

As an ancient organism whom currently occupies a large chunk of a planet beneath the surface, I have a pesky issue with an invasive species. These humans have decided to colonize my home, mistaking it ...
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0answers
67 views

What would plant life on 55 Cancri e be like? [closed]

55 Cancri e is an actual exoplanet which should be around twice the size of Earth so it would be high gravity. It also is thought to be a carbon planet, meaning the role silicate takes on our world ...
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3answers
1k views

A Decoy Planet made of expanded polystyrene. How big can I make it?

Note: This is different from the previous question Building a full-sized Lego Earth - what would it look like at various levels?. In that case it was about making a solid full-size Earth from Lego and ...
6
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2answers
507 views

Can a planet's rings be so thick that someone inside them can't see out?

For a SF story I'm wondering how thick a planet's rings can be? When viewed from the inside, can the ring material be so dense that visibility would only be a couple of meters? What would it take to ...
6
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4answers
233 views

Is the size of a portal going to limit the propagation of gravity through it?

It's a general question but my specific concern is whether different planets would crash into each other if a portal is made between them. We're assuming bare, naked, "hole in space" portals. This ...
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4answers
229 views

How can Mars have life but still be “The Red Planet”

Building on this question "Discovery of life on Mars" Mars is habitable (40% the mass of Earth, 6.06 m/s² gravity, escape velocity of 7.88 km/s, a satellite big enough to stabilize its axis and has ...
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17answers
7k views

Need a specific event that wrecks the surface, allows the race to survive in bunkers, and affords an aftermath suitable for them to rebuild

One rule: it cannot be caused by aliens or AI invading the planet. But it is okay if an alien race causes the destruction in any other way. It's an Earth-like planet. I need the effects of the ...
8
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1answer
677 views

If the Earth was part of an ultimate solar system, what would the sky look like?

I once show a picture depicticting the idea of an ultimate solar system: Image Copyright Sean Raymond In this solar system there are 8 planetary orbits, each containing 52 equal-mass, evenly-spaced ...
8
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3answers
342 views

Life on giant planet | Can centrifugal force reduce gravity?

In my world a space civilization is colonizing a massive solid planet. The planet has an extraordinarily fast rotation. The gravity is severe at the poles, making life impossible, but life flourish ...
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3answers
1k views

What is the Habitable Zone of a Red Dwarf star?

This question is pretty straightforward: What is the minimum and maximum distance for a planet to be in the habitable zone of an average sized (not biggest, not smallest) Red Dwarf star?
7
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1answer
251 views

What would a world-ending meteor impact look like from the ground?

I've read a lot of questions about the specifics of meteor impacts on this site, but strangely this one seems to still elude me: Assume a meteor of sufficient mass and speed to wipe out human life ...
7
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3answers
914 views

Life on a gas giant?

I know of the conceptualized "Sinkers", "Floaters" and "Hunters" that Carl Sagan and Edwin Salpeter of Cornell conceived of - as possible life forms that might inhabit a gas giant. At the time they ...
5
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5answers
452 views

What are the day and night fluctuations for a moon orbiting a planet the size of Jupiter?

In a nutshell, I'm trying to build a world with erratic day/night cycles. To get the erratic days, I'm working with a habitable moon. It takes 3 full earth days (72 hours) for the habitable moon to ...
8
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5answers
2k views

Distance between star systems

I'm writing a story that will eventually escalate from being focused on one planet to the entire star system that planet belongs to, and finally to a big story involving the two nearest star systems ...
9
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4answers
3k views

Desert planet with forests at the poles

I'm thinking up a Mars or Venus type planet where the poles (or one pole) has a forest growing out of it due to a device that is used to make the planet more habitable by creating a oxygen friendly ...
2
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2answers
140 views

How can I destroy a planet with antimatter?

So I found the base of these pesky rebels on this planet and I am tasked with destroying the planet to eliminate the rebels once and for all. Unfortunately, my death star has malfunctioned and has ...
4
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4answers
826 views

Could a terrestrial planet have water for a core?

There’s a planet called eaglypt whose surface is 100% barren desert. However, there is a twist: the planet’s core consists of liquid water, and there are a few places where this water seeps through ...
4
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3answers
615 views

Building a full-sized Lego Earth - what would it look like at various levels?

Lego representations of Earth have been made at various scales, for example this one: Suppose Slartibartfast made a full-size Earth from Lego (including the oceans being represented as solid blocks. ...
4
votes
2answers
74 views

Stellar and magnetic parameters for creating polar radiation hazards

I've got a generally earthlike planet, but my goal is to make radiation exposure in the polar regions a much larger hazard than it is on Earth, while not being an issue in other regions. Nothing ...
3
votes
3answers
246 views

What 4D shape could best fit a looping world?

I have an idea for a world such that the world itself is like a large loop. The best way I can think to describe it is going step by step through the "loop". Imagine a planet-like object; a sphere ...
3
votes
3answers
251 views

How does having 3 moons change a planet?

I'm working on a story that takes place on a world that has 3 moons. At least 2 of the moons are the same size. They align extremely rarely. Otherwise, it's an earth-like planet. There is one ...
2
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2answers
157 views

What would happen to the Earth if it were suddenly transported to a completely empty void? [duplicate]

The entire planet Earth is suddenly teleported (never mind how for now) to a completely empty space. No sun, no moon, no stars or other planets. There's absolutely nothing out there and it appears ...
2
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0answers
104 views

How long would it take to recover from a galaxy-wide war? [closed]

The Great Galactic War has ended. The evil Tatian Empire has been destroyed, and a new power, the Aurean-Ishga Republic, has risen from the ashes. However, there has been tremendous damage done to the ...
6
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2answers
130 views

Maximum realistic salinity level with thriving aquatic environment?

I'm trying to create a planet which environment is not immediately lethal to humans, (reasonable oxygen level) however after closer inspection turns out not to be specially Earth-like. One issues is ...
3
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4answers
162 views

Underground Atmosphere

I have a terrestrial planet that is similar to Mars in many ways, a desert-like surface, thin atmosphere, and inhospitable to large flora and fauna as we know it. This planet has ceased tectonic ...
3
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0answers
49 views

Downsides of a Magnetosphere stronger that Earth's? [duplicate]

It is clear that a planet that possesses a weaker magnetosphere than that of the Earth will present issues (such as less protection from stellar radiation) to a potential human colony. However, are ...
4
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0answers
35 views

Can a solar flare or coronal mass ejection cause a planet to heat up? [duplicate]

There is this setting I wish to use of a planet tidal locked to a red dwarf, in a Goldilocks/habitable zone/distance, that gets turned into, mostly, a desert due to a coronal mass ejection or a solar ...
40
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22answers
8k views

How can you prevent a theocracy from being inevitable when religious leaders have power over nature?

In this world, religious leaders of a world religion practice a form of ritual magic that is essential to human existence. Certain rituals must be performed at certain times for nature to function ...
7
votes
10answers
281 views

Plausible reasons for multiple hot seasons in one solar year

Setup: A planet generally with an earthlike climate, although slightly wetter and warmer as a general rule, with a little more oxygen in the atmosphere, but habitable by unmodified humans. Still has ...
7
votes
1answer
138 views

Could a Moon have its own “Rings”, like Saturn's, without the Host Planet having them?

I'm currently fleshing out a sci-fi universe and always looking for fun new locales to populate it with, and I saw this phenomenon in a video game I've been playing recently, and it made me curious... ...