Questions tagged [planets]

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

Filter by
Sorted by
Tagged with
195
votes
28answers
29k views

I'm stranded on an alien planet. How do I measure an earth year without a clock?

I just got shoved through a stargate onto a planet I don't know. I was told the gate would open again in exactly one Earth year. I wasn't carrying anything; I don't even have my watch. How do I know ...
116
votes
17answers
13k views

Which major solar system body could most realistically be artificial?

Which body in the Solar System is the best candidate for being an artificial construct, placed there by a Kardashev Type II Civilization? Some notes: The purpose of this body is to monitor earth, ...
116
votes
18answers
32k views

Could a planet made completely of water exist?

In the Star Trek: Voyager episode "Thirty Days", there was a planet made completely out of water, which is the inspiration for this question. However, that planet was held together by an artificial ...
104
votes
18answers
21k views

What would make scientists realize they were on a flat world?

Scenario: While poking around in an alien ruin, scientists discover a gateway which offers instant transportation to an Earth-like world. The Observed World: The gateway leads to an area that is ...
104
votes
6answers
28k views

How would having multiple moons affect tides?

We know that planets can have multiple moons, sometimes quite a few (like Jupiter). Assuming that a planet with several moons were habitable in the first place and has significant oceans (greater ...
89
votes
13answers
17k views

A mosque on Mars?

Premise Mars has been terraformed and has seen its first few stages of large-scale colonization. The colonists are middle to upper class Earthlings. Earth is not a dystopian planet per se, but Mars ...
71
votes
20answers
6k views

Is it physically possible for a planet to have seasons of different lengths?

Those of you who have read Game Of Thrones will know that in the GOT world seasons do not have a fixed duration, e.g., a winter might last three times longer than the previous one. I find most ...
70
votes
17answers
17k views

How can I move a planet?

There are a lot of answers on Worldbuilding about how to destroy planets - just as an example - and they seem to be the method of choice for many people intent on destroying the world. My objection to ...
68
votes
6answers
11k views

Would earthlike planets in other solar systems have well-known Earth gemstones such as rubies, emeralds and sapphires?

I'm currently working on a conworld that has never had any contact with Earth, and I'd like to create words for iconic gemstones, such as rubies, emeralds and sapphires. However, I can't help but ...
66
votes
5answers
3k views

Are geographically typed planets realistic?

In many science fictions we see planets which are designated by a particular terrain type. For example, Dagobah is a swamp planet, Tatooine is a desert planet, and Kamino is an ocean world. However, ...
65
votes
24answers
9k views

The opposite to Worldbuilding: World Destruction

I am looking at different ways to destroy a planet. I am assuming the planet is of a similar size and composition to the Earth just to keep things simple. I am starting at boiling the atmosphere to ...
58
votes
14answers
32k views

Would the human body support living on planets with a greater gravity than Earth?

I once read a novel about a prison-planet which was chosen to make the prisoners suffer. One of the different "tortures" was a gravity three times higher than that on Earth. Would the human body ...
57
votes
10answers
12k views

What would it feel like on the surface of a planet while it collides with another planet?

Let's say that something horrible has happened and a Mars-sized planet is knocked out of orbit and is hurtling towards an Earth-sized planet. How much time will they have? How will this affect the ...
56
votes
9answers
15k views

What impact would a dragon the size of Asia have on the environment?

Without going into unnecessary detail, one of the races of my world believe that the land itself is a dead god, and that by resurrecting it, it will ascend to the cosmos and carry the faithful upon ...
53
votes
21answers
4k views

Planetary Scale Artworks

A highly advanced civilization has developed and is about to ascend to become beings of pure energy in a hyper-dimensional universe. Before leaving they restore our universe to a reasonably pristine ...
51
votes
27answers
13k views

If a large space ship crashes on a planet, what could kill passengers without obliterating the ship?

The situation I'm considering is as follows: A large research vessel with a crew of about 100-200 attempts to land on a potentially habitable planet, but something goes wrong during the descent. A ...
51
votes
16answers
6k views

What kind of recurring phenomena could cast darkness on a planet for days/weeks at a time?

A century ago, after a catastrophic event on our planet, many of us were were forced to find a new home. There was one world that caught our attention: a tidally-locked blue planet orbiting a red ...
50
votes
6answers
34k views

If we put humans on planets with atmospheres different from Earth's atmosphere, but still containing oxygen, would humans be able to breathe?

From Wikipedia: By volume, dry air contains 78.09% nitrogen, 20.95% oxygen, 0.93% argon, 0.039% carbon dioxide, and small amounts of other gases. For example, would humans be able to survive in ...
49
votes
14answers
6k views

How would they learn astronomy, those who don't see the stars?

I imagine a planet similar to ours, except for two details: The presence of everlasting clouds No yearly seasons Explanation: In this world clouds are very high and thick, so that sunlight (or ...
49
votes
6answers
10k views

Could two planets be tidally locked to each other so close they share their atmosphere?

Could two planets be tidally locked to each other at such a small distance from one another that they share their atmosphere, and material is floating around between the two?
49
votes
4answers
5k views

What would a planet spinning fast enough to allow geostationary orbit near the surface look like?

From an answer to a previous question of mine: A planet spinning fast enough to allow geostationary orbit near the surface would result in odd side effects. Any object at rest on the equator would ...
48
votes
13answers
10k views

How large would a world have to be for a sailing ship to never make it past the horizon?

I have a sailing ship. It leaves port. As it goes away, it grows smaller and smaller. In our world, it eventually is hidden by the curvature of the Earth, such that the top mast stays visible longer. ...
48
votes
12answers
6k views

How would a Martian colony be able to celebrate Christmas?

Accept that we had a reason to go to Mars, managed to build a colony there, and what we found on Mars is valuable enough to ship back to Earth. There is now a self sustainable colony living under the ...
47
votes
2answers
4k views

What would the sky look like from the surface of a planet with rings?

What would a planet's rings look like from the surface of that planet? Would the rings be perceived to be stationary or move across the sky, and would the alignment of the rings relative to the axis ...
46
votes
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 ...
45
votes
19answers
11k views

Can there be a planet with no dust?

What restrictions this planet must have to make it possible? Planet can have any size, be made of any material A human must be able to land in it and observe it, dust added to the planet from the ...
45
votes
8answers
7k views

Can two adjacent, life-sustaining planets orbit a star such that they are rarely near each other?

I have two planets and humans live on both of them. Humans need not have developed on these planets, but the planets should support human life with the allowance that the humans have technology ...
44
votes
12answers
9k views

Could two planets follow the same orbit and never “see” each other?

Imagine two identical planets planet A and planet B, orbiting the same star. Is it possible that these two planets follow the exact same "route" as they orbit their sun, but are just distant enough ...
44
votes
5answers
7k views

What are the safety margins for destroying a planet from space?

My empire's flagship, the Persecutor class UJBHE1 Abhorrent, rides into the home system of my greatest enemy, Baron Obsequious, levels its Death Ray2 at his beloved home, and pulls the trigger.3 ...
43
votes
23answers
10k views

What would be best way to re-melt Mars' mantle and core to revive its magnetosphere

Missing magnetosphere on Mars keeps popping up. Most likely caused by Mars core being cold, mantle not bubbly enough. Mars mantle is dormant, core does not move. What would be good way to get it ...
42
votes
7answers
10k views

What's the largest body in the solar system that you could destroy without endangering humanity?

You're an alien that really likes pyrotechnics. Nothing that goes boom on your home planet (in a safe and responsible manner) satisfies you any more. Why not blow up a planet and see what that's ...
42
votes
3answers
5k views

So we glassed it, now what?

"Glassing" a planet is a common ultimate tactic in Science Fiction, basically it consists in using high power energy weapons to destroy all life on the planet and reducing the soil and rock of the ...
41
votes
5answers
6k views

How do seasons work in a binary system (planet orbits one star, not both)?

I have a planet orbiting one star in a binary system. When the planet is exactly between the two stars it will experience a double day; when the primary sun sets the secondary one rises, no overlap. ...
40
votes
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 ...
39
votes
20answers
9k views

Reasons why air travel isn't feasible, but ground travel is?

My story takes place on an Earth-like, inhabited world that is far larger than Earth, has roughly 110% of Earth's gravity, and has unusually high (and generally unexplained) EM emissions permeating ...
39
votes
6answers
7k views

Planet wide seasons: Possible?

I was reading a World Anvil article which has a world that experiences world wide seasonal changes. Specifically quoting the article, During the month of Frimense, the Frostkin thrive, as the ...
38
votes
16answers
5k views

Resources to justify long-distance space mining missions

Earth is setting up mining colonies on Tau Ceti e. But how can they justify the enormous cost of sending people there? ...Because during the initial exploratory missions, it was discovered that in ...
37
votes
10answers
11k views

How can I destroy a gas giant planet?

We have already discussed how difficult it would be to blow up a planet like Earth, basically deciding that you can't do that with any reasonable amounts of energy. But what if I don't need to blow up ...
37
votes
11answers
5k views

Stumped: How can I get a huge Earth-like planet?

I hope this isn't too broad. I would like an Earth-like planet for November's NaNoWriMo that is just enormous, but plausible. Then I started to get into material composition, proximity to the star, ...
37
votes
7answers
8k views

Can 3 planets rotate around each other like this?

I was wondering if three planets can rotate around each other so that: Two of the planets are smaller and rotate around each other Both of the smaller planets rotate around another, bigger planet. ...
37
votes
5answers
7k views

Can a planet survive a supernova?

The Sun has nowhere near enough mass to enter the branch of stellar evolution that would lead to a supernova, fortunately for us. However, there are planets that orbit stars that are destined to go ...
37
votes
2answers
10k views

How would winds behave on a tidally locked planet?

If an earth-sized planet were tidally locked to a star, and was in the life zone of its star with an earth-like atmosphere, what would its wind patterns be like? The planet would have one hot ...
36
votes
14answers
6k views

What conditions would prevent the possibility of human-made satellites orbiting a habitable planet?

I'm looking for something that would prevent humans being able to establish the use of satellites on an alien planet, but also would not prevent humans from living on the planet, or life developing on ...
36
votes
5answers
6k views

Can a planet realistically have multiple suns?

Several science fiction books I have read (including, IINM, Nightfall by Asimov) have featured planets with several suns. Some worlds where this happened wrought interesting effects on the inhabitants ...
36
votes
8answers
9k views

How extensive could a habitable twilight zone be on a tidally locked planet?

If a planet always faces the same side to the sun, so that it has a permanent night side and a permanent day side, it will have a twilight zone in between the two sides. This will be a band around the ...
36
votes
3answers
7k views

Habitable moon of a gas giant: working out the sizes and distances

I am attempting to create fictional, stable P-Type binary system, featuring a gas giant in a stable orbit, with a habitable Earth-like moon. “Is a Jupiter-sized planet plausible in a habitable zone?” ...
35
votes
6answers
5k views

What's the smallest reasonable natural planet or moon with Earth-like surface gravity?

We all know that equation for surface gravity is $$ g = \frac{4\pi}{3} G \rho r $$ So if we want Earth-like surface gravity of $ g = 9.81 $, then the equation for radius is $$ r = \frac{3 g}{4\pi G ...
35
votes
4answers
3k views

How large could a planetary diamond be?

Back in the days when men were real men, women were real women, and small, furry creatures from Alpha Centauri were real small furry creatures from Alpha Centaury, an obscenely rich woman decided she ...
34
votes
7answers
6k views

Could you float a boat on a gas giant?

A futuristic entrepreneur wants to start a cruise line company and needs to build a cruise ship that will not only float on a gas giant, but be habitable throughout a 7 day trip (for the uber-rich of ...
34
votes
5answers
4k views

That's no Moon: Planet-sized Plants Possible?

Inspired by the many great questions asked for this fortnight's tag challenge, I got to thinking, could a plant develop/evolve to eventually consume an entire planet, and keep on living? What I mean ...