All Questions
26 questions
3
votes
6
answers
1k
views
Plausible orbit to have a visible object slowly circle over the night sky
I want to have the inhabitants of a particular world - doesn't have to be a planet, can be a moon - be able to see a certain point of light - can be a planet, moon, star, whatever - moving in the sky ...
- 739
0
votes
2
answers
383
views
Implications of Venus and Mars having the same mass as Earth
Could anyone advise if there have been any simulations on the long term stability of our solar system if Venus and Mars both had the same mass as Earth ?
If not, is this something that can be answered ...
- 9
1
vote
2
answers
159
views
Reverse engineering the Hill Sphere?
I'm wondering if anyone has run into the issue of "I know the general idea of how big my moon is but not the parent planet" and how to sort of reverse engineer finding out the mass/radius of ...
0
votes
1
answer
71
views
Can an earth-like planet exist in a circumbinary orbit around two k-class stars?While also having up to two dozen other planets in circumbinary orbit?
I have a plot arc in mind, but it all hinges on the feasibility of an earth-like world existing in circumbinary orbit around two k-class (or g-class) stars. The looming danger in the story arc is that ...
2
votes
2
answers
153
views
How fast should my planet spin in order to be tidally locked?
I am designing a habitable planet with a diameter of 12.879 km. orbiting around a K5V orange dwarf star. Due to a number of planetery collisions during its creation, the planet ended up being tidally ...
- 1,811
17
votes
5
answers
3k
views
Where could we add a new planet to the inner solar system?
Assume there was a super advanced alien race that for some reason, wanted to add a new planet, of lets say 1 Earth mass, into the Solar System. Where in the inner Solar System (The part of the solar ...
- 2,197
8
votes
6
answers
593
views
Could an Irregular Orbit Cause Significantly Longer Seasons?
I have a fantasy world I'm making, with a planet and sun similar to our world, except the length of the seasons are significantly longer. Each of the seasons last two years, and the full seasonal ...
9
votes
2
answers
743
views
How to Calculate Apparent Magnitude/Brightness of Planets from Within the same Solar System
I'd like to be able to determine the appearance of the night sky from an Earth-like planet, in a solar system with multiple other planets, moons, and other bodies. Here on Earth, we can directly ...
- 842
6
votes
2
answers
243
views
Binary World Mechanics
I’m trying to develop a realistic system with a limited understanding of astrodynamics.
Is it possible to have two binary worlds capable of sustaining atmosphere and complex life orbiting one another ...
- 289
16
votes
4
answers
6k
views
Can planetary bodies have a second axis of rotation?
Is it possible for a planetary body to have a secondary axis of rotation? For example let's say there's an Earth-like body that is spinning with its North Pole facing the Sun. Imagine that the North ...
- 6,322
3
votes
1
answer
425
views
How long can a moon remain non-spherical, and what might it look like when full?
I'm trying to "build" a world in which the moon is always visible at night, and only at night, to the majority of areas on that world. I've been told that an L2 Legrange point could be a viable ...
- 31
6
votes
3
answers
846
views
Replacing Jupiter with a brown dwarf?
This is a purely hypothetical question but I can't find a satisfactory answer to it.
Let's say somehow Jupiter collects enough mass to be considered a brown dwarf. Let's assume Jupiter achieves a ...
- 995
24
votes
5
answers
4k
views
What do Martians use for months and weeks?
Assume Mars has developed an indigenous civilization of its own, perhaps as seen in Edgar Rice Burroughs' A Princess of Mars.
Much like Earth, Mars' years and days would be significant for any ...
- 85.8k
2
votes
4
answers
247
views
A planet with a diurnal cycle on only one hemisphere?
I need a habitable body with 64-hour days and nights... but only on one hemisphere. The other side is perpetually dark.
Is such a thing possible? I'm picturing a tidally-locked moon orbiting a gas ...
- 335
4
votes
1
answer
326
views
That's a big planet, but how big is it?
If a tidal locked terrestrial sized moon with 0 eccentricity, 0 incline, and was orbiting .01 AU away from a gas giant with 12 Jupiter masses (which would have approximately the same radius as Jupiter)...
- 159
2
votes
4
answers
2k
views
Could a habitable tidally locked planet have a day and night cycle caused by the eccentricity of its orbit?
I'm trying to think of ways that a habitable tidally locked planet could have something that resembles a day/night cycle. Shadows caused by any moons being out of the question.
Hypothetically, could ...
- 1,252
6
votes
5
answers
949
views
Making a slow orbit around a large gas giant
First of all, this website is a dream come true. I'm a total sucker for this stuff.
Secondly, I love astronomy and worldbuilding, and lately, I've been thinking of a hypothetical situation, and was ...
- 61
7
votes
1
answer
1k
views
Is this circumbinary planet set up in a stable manner?
This is the ideal set up for my solar system:
EDIT
It's been pointed out that this is not a stable set up, so I want to clarify that everything in this set up can be changed at will to fit my planet. ...
- 901
17
votes
6
answers
5k
views
How would a torus world (donut shaped) have to rotate in order to have a stable day / night cycle in all of its regions?
In this universe, mass and gravity work differently so stable torus planets are possible (donut shaped).
How would a torus world orbiting a single star have to rotate in order to have a stable day ...
- 1,252
7
votes
4
answers
1k
views
How can a planet orbit two or more stars simultaneously?
What would the orbit of a planet orbiting two stars look like? Would the planet orbit the stars simultaneously or one after the other? How strong might be the gravity well of such a system be? Any ...
- 304
3
votes
1
answer
176
views
Moon rotation & orbit periods differs - can it be made feasible?
I have a mars-sized "planet" orbiting a superearth-sized mother-planet. There is also another satellite with an abnormal elliptic orbit, but it is of minor concern for now.
This is the resume of ...
- 141
8
votes
1
answer
2k
views
The (Alternative) Reason for the Seasons: Highly Eccentric Orbit
On Earth, we experience seasons because of our planet's axial tilt.
It is a common misconception that the seasons are instead caused by our planet's distance from the sun changing as it orbits. The ...
- 4,797
3
votes
2
answers
196
views
Planet trajectories in a made-up night sky
The people from my made-up world are strong believers in astrology. Their culture and religion revolves around the relative positions of the planets of their solar system.
Are there any resources (...
- 5,808
41
votes
3
answers
13k
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?” ...
- 1,518
19
votes
4
answers
2k
views
How would two planets with identical but perpendicular orbits affect each other?
I'm exploring this idea for a fantasy world, and I was wondering how these planets would affect each other. The system would feature orbits in all three dimensions, not relatively flat like ours is.
...
- 343
82
votes
21
answers
10k
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 ...
- 2,177