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Questions tagged [day-night]

For questions regarding the day-night cycle of a day on a world. Usually regarding the dark-light cycle.

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What's the effect of increasing the Earth's rotation on climate?

The Earth's rotation speeds up slowly but without limit. How does this affect the climate? I am thinking that day and night temperatures would even out so that there would be less wind, but I don't ...
spraff's user avatar
  • 2,239
3 votes
1 answer
99 views

How might seasons work on Alpha Centauri Cb?

(first post from a writer drafting a sci-fi novel, so please forgive any ignorance or missteps and TIA!) Let's say Alpha Centauri Cb is habitable, under these conditions: Air quality capable of ...
reiterwriter's user avatar
1 vote
0 answers
95 views

How do I make a Lunar Calendar for a planet with three moons and two suns on either side? [closed]

The planet is about three to five times the size of Earth and it shares a solar system with 13 other planets and they have an ∞ shaped orbit around two suns on opposite sides of the solar system. The ...
Los3r_ghost_tale_factory's user avatar
1 vote
3 answers
123 views

How long would a day/week/month be in a world where a year was the equivalent to four months here? [closed]

I am new here and I wish for someone to help me with this question that haunts me with writer's block. I am writing a story that is set in a world where each year lasts the same time as four months ...
Los3r_ghost_tale_factory's user avatar
2 votes
2 answers
230 views

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 ...
Curious-7's user avatar
10 votes
1 answer
376 views

If the Earth had 48 hour days, how much would the temperature drop at night and raise in the day?

I'm building a world that's essentially identical to Earth, except that it spins slower, making the days about 48 hours long. I'd like to know what the average temperature drop at night would be, and ...
Mocascoolai's user avatar
11 votes
5 answers
2k views

How fast does this planet have to rotate to have gravity thrice as strong at the poles?

For those of you who have read mission of gravity, or researched Saturn’s equatorial bulge, you will know that the faster a planet rotates, the greater the “flattening” effect it’s rotation has. This ...
user98816's user avatar
  • 8,593
3 votes
2 answers
204 views

Equations for converting axial tilt to hours of daylight

I have a world that I am intending to give about an 18° axial tilt. I know generally that this will reduce seasonal variation in the length of daylight (sunrise to sunset), however, what I'm unsure of ...
A Herrera's user avatar
4 votes
4 answers
417 views

Why does daytime on my planet resemble twilight/dusk?

The setting is science-fantasy, so there are some unnatural features that dictate the properties of the setting, but I'd rather not rely on it. So basically this planet is very similar to our own, but ...
Demiurge777's user avatar
3 votes
1 answer
89 views

How do I approximate sunrise and sunset times in this simplified model of a solar system?

For a small game I'm working on I'm interested in simulating a basic celestial model for a planet, two moons and a sun. The main use is determining when specific eclipses happen and what type they are,...
Loid Thanead's user avatar
  • 1,363
0 votes
2 answers
126 views

Day/night cycle on an S-type planet

[Answered myself below] I've seen similar questions have been asked before, but the details are slightly different. Say you have a tidally-locked, roughly Earth-mass rocky planet in the habitable zone ...
DMacc1917's user avatar
  • 946
5 votes
1 answer
268 views

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 ...
Bangerton's user avatar
1 vote
1 answer
152 views

What would happen to the climate if the poles reached equatorial temperatures every summer (but sub-zero temperatures in winter)

I'm not asking about mercury level differences; the planet isn't melting daily and freezing nightly, but I've been thinking about this sort of thing for a specific planet I'm working on, one with an ...
Quinn's user avatar
  • 1,206
4 votes
3 answers
274 views

How large, slow, and/or close would the moon need to be to block the sun for at least a few hours?

Suppose everything about our world is consistent. I will tweak it from there. Alternatively, reverse it; suppose the moon was habitable and the planet hostile. How large, etc, would that planet need ...
Quinn's user avatar
  • 1,206
0 votes
3 answers
162 views

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 ...
user98816's user avatar
  • 8,593
3 votes
1 answer
244 views

What would the stars look like near the centre of a galaxy?

In this sci-if scenario, angry aliens “evict” Earth and the sun from the galaxy using their clarkean wormhole technology, and sol ends up in a new region of space. Sol is now located near the core of ...
user98816's user avatar
  • 8,593
21 votes
9 answers
9k views

How long would humanity survive if a sudden eternal night occurs?

It's a normal victorian era day until people start to realize that the night is taking too long to pass and the sun is not coming out, in fact the sun is never coming out again. The sun still exists ...
Mark T's user avatar
  • 321
13 votes
9 answers
3k views

Possible explanations for abnormal day/night cycle?

This is my first question here, so any help would be greatly appreciated. I am trying to figure out how my world's day and night cycle works, or if something like what I'm hoping for is even possible. ...
Sidra Klyara's user avatar
4 votes
3 answers
82 views

How to prevent the effects on gravity, climate and day-night cycles on a "planet" with a surface area nth time as big as earth's?

In my story, one key feature is that the earth-like planet or habitat has a surface area of earth > 10 times. However, as it is inhabited by pre-industrial humans that might have been brought on it ...
Fields of Blue's user avatar
9 votes
14 answers
3k views

Is it plausible for a world without an external universe to develop a year system?

I'm currently in the phase of planning a time system for my world and I am starting to run into logistical issues. My world essentially is an island in an endless ocean. No universe, no rotation of ...
violetorigin's user avatar
6 votes
4 answers
997 views

What is a reasonable day length for a planet with 4 times earth radius?

The fictional planet has a mass of 18 times Earth's and four times earth's equatorial radiusreference. This gives it a gravitational acceleration of 11.02m/s^2 (1.29G) and an escape velocity of 23....
Mindwin Remember Monica's user avatar
5 votes
1 answer
190 views

How would short nights affect human life?

My world is a flat disc, with a sun orbiting around it, and a stationary moon in its center whose shadow simulates nighttime. Due to this, the central and outer regions experience a state of perpetual ...
ognjen's user avatar
  • 53
8 votes
6 answers
5k views

If Earth had a smaller radius, but was rotating at the same speed, would its day be shorter?

I want to make a hypothetical planet that is 26% the mass of earth, with 64% the radius. Because I want a relatively short day to keep temperatures more stable, but I don't want a super fast rotation ...
Elhammo's user avatar
  • 975
4 votes
2 answers
94 views

Can an Earthlike planet orbiting a K-type star have longer days and extreme thunderstorms?

The planet orbits a K-type star. Basically same gravity as Earth's, with similar atmosphere. I'd like it to have a 30-hour day, plus in my characters' region, occasional very bad thunderstorms. Think ...
K C.'s user avatar
  • 41
0 votes
2 answers
117 views

How bright would these four stars look on the planet you're standing on right now?

Most of the numbers here have been plugged to me by someone you would find on both Reddit and the Speculative Evolution Forum. Imagine yourself standing on a planet in a quaternary solar system. The ...
JohnWDailey's user avatar
  • 14.5k
0 votes
1 answer
99 views

In this binary, how far would the secondary planet orbit the primary planet and still have its own day-night spin?

A scenario I've been exploring lately: Orbiting a binary of G0 stars (each one 105% as wide, 110% as massive and 126% as bright as our sun) from a distance of 2.065 AUs is a planetary binary. The ...
JohnWDailey's user avatar
  • 14.5k
4 votes
5 answers
258 views

Endless global night.. but an agreeable climate, how come?

How would my planet develop an acceptable climate, without a sun ? There is no (visible) sun, but the climate permits STP, and there are 1 or more luminous, rocky moons providing some light. Perhaps ...
Devsman's user avatar
  • 3,530
-2 votes
2 answers
395 views

Can owls, cats and others visual nocturnal animals see in moonless nights?

Im working in a moonless xeno planet and i want nocturnal creatures. I have animals that use smell, ear and touch, but im not sure about vision. I mean, animals and persons need a tiny bit of light ...
Krakukan's user avatar
  • 203
2 votes
4 answers
224 views

Day/night in Aether

An extremely powerful wizard decided to create a new dimension as a birthday present for his wife, this dimension is composed of flying islands inhabited by fantastic plants and animals. The islands ...
Wizard King's user avatar
  • 2,694
3 votes
3 answers
784 views

Climate on a slow spinning planet

I'm currently working on a story set in a planet whose rotation period lasts around 24 years (Earth years, or 8766 days). This planet orbits at more or less 0,75 AU from a K-type star, and the ...
MoholyNagy's user avatar
  • 1,107
5 votes
4 answers
414 views

A Planet Approaching being a tidally locked planet

I am world-building an adventure for the Alien RPG. As a world approaches being tidally locked, and by this, I mean in the process of slowing down, but not stable. In such a world that no longer ...
RixRam's user avatar
  • 53
1 vote
1 answer
106 views

Would 6 Earths Separated by 60 Degrees Have Day-Night Cycles?

This picture is taken from one of Sean Raymond's Planet Planet articles, Cohorts of co-orbital planets. What the article doesn't explain, however, is the basis for the question. In a solar system in ...
JohnWDailey's user avatar
  • 14.5k
4 votes
3 answers
298 views

How would a planet's (human) life adapt to inconsistent night duration?

I realise this question is rather broad, so I'll do my best to narrow down what I'm looking for as much as possible. The big idea The full daylight cycle on this hypothetical planet is consistent in ...
Nate_Nitro's user avatar
6 votes
2 answers
246 views

If John Atkinson Grimshaw's Paintings were actually daylight, what kind of star would this "sun" be?

An Englishman by the name of John Atkinson Grimshaw was known only for his nocturnal paintings of the British landscape. I don't know about you, but his nocturnes have struck me as a bit...bright. ...
JohnWDailey's user avatar
  • 14.5k
1 vote
1 answer
4k views

What Would the Sky Look Like If the Sun Were a Different Color (And Still Half a Degree Wide)? [duplicate]

This question has been asked many, many, many times--what would the sky look like if the sun were a different color? But the mistake I keep seeing is that they used actual stars and imagined Earth as ...
JohnWDailey's user avatar
  • 14.5k
14 votes
5 answers
4k views

Could We See a Lagrange Giant in the Sky?

The "Lagrange giant" in the title refers to a gas giant that orbits its star in the same distance as Earth does. The alternative description is "Trojan planet" or, to be most ...
JohnWDailey's user avatar
  • 14.5k
4 votes
2 answers
438 views

How bright is night on a moon orbiting a gas giant?

I have an Earth-like moon tidally-locked to a gas giant that is Saturn-like but without rings. On the side facing the gas giant, how much brighter would nights appear when the gas giant is fully ...
B. T. Newberg's user avatar
4 votes
4 answers
407 views

What forms of life would be best adapted to living on a world with nine year long days?

Let us suppose that instead of the 24 hour cycle we currently enjoy on Earth between day and night, we instead lived on a planet with a day/night cycle that lasted a full 9 years. The noon of the day ...
TrEs-2b's user avatar
  • 56.2k
2 votes
1 answer
206 views

Life in the Temperate Zone of an Alternate Earth with an Axial Tilt of 42 Degrees--What Would the Seasons Be?

Suppose that in an alternate universe, Earth has an axial tilt not of 23.5 degrees, but 42. This means that from the equator, tropical climates with binary seasons (wet and dry) would persist from as ...
JohnWDailey's user avatar
  • 14.5k
4 votes
3 answers
838 views

Logistics of habitable moons orbiting a brown dwarf

Okay, so I've found some threads about the day/night cycle and seasons of habitable moons orbiting gas giants, but what if we replace the gas giant by a brown dwarf (i.e. the sub-stellar object class ...
WordNerd's user avatar
4 votes
2 answers
300 views

What is the ideal day length for extreme weather?

This question is in reference to a previous question by TrEs-2b and SRM: I want to create a planet with a significantly longer day than Earth's. However, I was only able to find a question about a ...
Mandelbrot's user avatar
  • 1,583
4 votes
2 answers
174 views

How could a planet with a long day-night cycle naturally regulate its temperatures to allow life?

So, my planet has (around) an Earth year long day-night cycle. How could its temperatures not reach extremes that would disallow life? Assume that everything is Earth like except for multiple moons (...
Username reset's user avatar
3 votes
2 answers
542 views

Temperatures of a planet with 1,000 Earth day long day-night cycle

My planet is Earth like in size (I can change it, if needed), however its day-night cycle is somewhere around 1,000 Earth days long. How hot would day get, and how cold would night get? Is it possible ...
Username reset's user avatar
1 vote
2 answers
404 views

How Bright Would Super Saturn's Rings Be in Our Sky?

It's not that long ago that we have found the "exoplanet" J1407b, notable for having a ring system 200 times the size of Saturn's. I airquote that term because, at a mass ten to forty times ...
JohnWDailey's user avatar
  • 14.5k
1 vote
1 answer
61 views

Animals, plants, and sleep cycles on a moon with a very long day-night cycle [closed]

Let’s say that this moon is about the size of Earth. Let’s say that our moon has a very long day-night cycle; about an Earth year. During night, would all plantlife die because of the lack of light? ...
Username reset's user avatar
6 votes
8 answers
711 views

Could a planet with many moons see a different moon each night?

This is just an idea I have been toying with. Taking Earth as an example with 7 days in a week, my idea would that there would be 7 moons in orbit around the planet. They would not necessarily share ...
LearnedStudent's user avatar
2 votes
0 answers
59 views

How long would daytime and nightime be on a planet with a 26 hours rotational period? [duplicate]

The basics about the planet in question: As the second planet in the star system, it's somewhat warmer than Earth is. The rotational period is 26 hours and the orbital period is 312 days which ...
1995inHUN's user avatar
  • 604
1 vote
2 answers
335 views

Would this sort of climate be possible on a tidally locked moon? [duplicate]

In the current fantasy novel I'm working on, I decided that I wanted to have a part of the planet where it was always daylight. After doing some research I learnt about the concept of tidally locked ...
Habiba Dokubo-Asari's user avatar
10 votes
4 answers
2k views

What would days and nights look like on this cylindrical world?

This is yet another "literal worldbuilding" question, as in, building worlds. Inspired, in part, by this question. What if this world is a very long (effectively infinite) hollow cylindrical cavity ...
Yuriy S's user avatar
  • 1,417
19 votes
6 answers
4k views

I want ten Earth-years long day on my planet. Can I have it?

I need ten Earth years long day-night cycle on my planet. Hemera is a world I am creating as a setting for my story. Name comes from Greek deity - personification of Day. Needs of storytelling have ...
Zjerzy's user avatar
  • 616