Questions tagged [astronomy]
For questions related to planets, moons, stars and other celestial objects, and their motion on the sky.
614
questions
6
votes
2
answers
471
views
Is it possible for an asteroid belt to form around a sun?
Is it possible for an asteroid belt to form around a sun? Think of our asteroid belt, but instead of where it is now, it would be where Mercury is.
Also, and I didn't have enough room to put this ...
4
votes
2
answers
402
views
What would it look like for a planet with two moons and rings during a double eclipse?
Since we just had an eclipse, I began to think: what would it look like if a planet had rings and two moons?
Now, there are two solar eclipses going on at the same time! What would the sky look like?...
5
votes
5
answers
534
views
How could the government trick the entire world into thinking there will be an eclipse when there isn't?
In my story, the government is looking to get as many individuals as possible outside. Is there a way to convince the population that there will be an eclipse or some other astronomical event without ...
1
vote
1
answer
225
views
View the past by reflection? [duplicate]
I want to postulate that I have a sort of "time machine" that uses reflections from nearest planets to image places on Earth at a time in the past (2 x distance of reflector in light years). Is this ...
-1
votes
1
answer
177
views
Is it really possible to push a solar sail with a laser on a cosmic scale? [closed]
One solution to interstellar space travel that I have heard popularised is to construct a ship with a solar sail and then use a laser to push it away. The advantages are obvious; you don't need to ...
1
vote
1
answer
160
views
How would a noble gas lake form on an earth-like world?
Pretty much the title. I was thinking that it could have originated from a meteorite impact. I think that there are meteors that are made of frozen noble gases, so that would be the source of the "...
1
vote
7
answers
534
views
Feasibility and challenges of a kingdom existing within an eternal night?
Okay, so admittedly I was going for a title that was a bit more catchy than the actual question, but not by much. On a technical level, the real question is "Feasibility and challenges of why a large ...
13
votes
4
answers
4k
views
Can two moons orbit each other while orbiting a much larger planet?
Trying to work out mechanics and visuals from one of two moons orbiting a gas giant. My idea is that the moons are tidally locked so they can never see each other's backsides, but this might be ...
14
votes
9
answers
927
views
How to blow up a star by accident?
I have this race of space-dwarves and I need to make them homeless due to technological hubris of some kind: for plot reasons.
I think that if they were to attempt to build some kind of Dyson sphere ...
1
vote
3
answers
278
views
Spherical shape Galaxy - Is it possible or not? [closed]
can galaxies exist in spherical form?
If yes, can you tell me how is it possible and whats the size limit of such galaxy
If no, what is the reason it can't form spherical shape?
BONUS: How will you ...
5
votes
1
answer
4k
views
How to calculate the solar day from sidereal day and sidereal orbital period?
I know the orbital period of my planet and the rotational period of my planet. Now how do I calculate the solar day? It would only be a small difference to be sure, but do remember that if we didn't ...
2
votes
4
answers
356
views
How would a neutron star affect the habitability of planets orbiting a companion star?
A star system consisting of two stars forms, with one being more massive. As such, the larger star soon exhausts its fuel and ends up as a neutron star. The secondary star has a semi-major axis of 700 ...
69
votes
19
answers
17k
views
How would an astronaut conclude he's on Earth, but 600 million years in the future?
Say we have a group of space travelers who have been frozen inside a sleeper ship for an enormous amount of time that left when Earth was recognizable. When they thaw out and reach their destination, ...
4
votes
2
answers
278
views
What would happen if a planet was surrounded by an unusually large amount of dark matter/energy?
Let's say we have a planetary system that has somehow attracted an unusually high amount of dark matter and dark energy. We can hand-wave the physics and any impossibilities behind the method of that ...
4
votes
2
answers
1k
views
Can a planet with a very long day/night harbor life such as Earth?
The year of this planet is 1,000 earth-days-long around its star, and its night lasts half a year.
Can it support life such as Earth?
With humans and lush forests and liquid water and good ...
9
votes
2
answers
590
views
Radiation from binary star systems and how that would affect a planet orbiting both stars
I am working on a solar system for a world where I intend to place my stories. This world should work by the laws of physics as we understand them so that, even though magic is a thing that exists in ...
4
votes
3
answers
333
views
Human colony on distant planet system with very short day-night cycles
I need a planet where the day cycle is short, in particular 16 hours. I read What determines the length of a day on a planet? and Is it physically possible for a planet to have seasons of different ...
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 ...
4
votes
1
answer
284
views
How extreme can I make an altered solar cycle without destroying an inhabited world?
This is a follow-up to an earlier question. My intent here is to work out the details, and explore the potential consequences, of one of the many excellent answers I received. Relevant questions have ...
23
votes
11
answers
4k
views
Is it possible to have a sun with visible phases or cycles?
Is there a scientifically plausible way for a habitable world to have a sun that undergoes a regular, dramatic, and easily observable change? One comparable in visual impact to an event like a solar ...
5
votes
2
answers
418
views
How can I find local stars that are 'gravitationally bound', i.e. moving together?
Within our local region of space are several hundred/thousand stars. I had long ago found some pretty good resources and made a starmap (using YGraph and some star catalog datasets I got from Nyrath, ...
8
votes
3
answers
337
views
"Night" sky between galaxies
Say we're on a ship traveling between the Milky Way and Andromeda. We decide to stop and take a look out our space-windows.
What do we see?
I'm presuming that the Milky Way and Andromeda would both ...
32
votes
2
answers
3k
views
Would life on the edge of the Sagittarius Dwarf Spheroidal Galaxy see the whole Milky Way in the night sky?
Here's an intriguing thought - I think so anyway. Let's suppose for a minute that there's an Earth-like planet with sentient life orbiting a star near the edge of the Sagittarius Dwarf Spheroidal ...
1
vote
3
answers
130
views
Swapping the sunny side of tidally locked planet
For story reasons I need a situation with a planet around red dwarf, which already has had the equivalent of a Great Oxygenation Event. Simultaneously I also like the planet to be mostly without ...
10
votes
4
answers
3k
views
What is the habitable zone around my star?
I have built a star that is loosely based on a real-world star. It has the following properties:
Spectral class G
Mass: 1.03 M$_\odot$
Radius: 1.02 r$_\odot$
Luminosity: 1.05 L$_\odot$
Surface ...
11
votes
2
answers
7k
views
Does Earth's direction of rotation affect day length?
Let's say Earth started rotation in the opposite direction without any catastrophic events, would a day on Earth be shorter or longer or just the same considering that speed of rotation and revolution ...
24
votes
11
answers
4k
views
Can you replace a sun with a burning moon?
In our solar system light and heat are, of course, provided by the sun. I was wondering if a comparable effect might be had by positing a burning moon instead? So rather than a true star, you'd have a ...
12
votes
3
answers
2k
views
What would the star chart be like if earth had a ring?
Recently, I've seen those pictures showing what Earth would be like if it had rings, and that made me wonder, what would the sky map be like? This ring would appear as a fixed object (pretty much as ...
5
votes
1
answer
250
views
Effect of Hot/Warm Jupiter atmosphere loss on Habitable Zone
Let's suppose a solar system:
A main-sequence star similar to the Sun. G2V or so.
A Hot/Warm Jupiter HJ with a semi-major axis somewhere from 0.5 AU to 0.0001 AU.
An Earth-like planet EL with a semi-...
6
votes
5
answers
920
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 ...
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. ...
17
votes
6
answers
4k
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 ...
8
votes
1
answer
327
views
How would early astronomers prove the existence of a spherical firmanent around the Earth?
Someone made the Earth.
They placed man on the surface and gave them plants, animals, the waters, and the mountains to make their life compete.
The Earth exists within a spherical firmament upon ...
6
votes
6
answers
880
views
How could Earth quickly deorbit the Sun without being destroyed? [closed]
Conditions
Critical to the plot, Earth needs to be taken out of the Sun's orbit around 2050 (i.e., not destroyed; nor merely darkened via "indirect" solutions such as alien Dyson swarms surrounding ...
2
votes
2
answers
256
views
Environmental conditions on quasi tidal locked planet
There is an earth like planet, with similar mass, gravity, atmosphere and magnetic field. The main difference with earth is that it has a highly eccentric orbit (eccentricity 0.8).
Let's say that the ...
5
votes
2
answers
839
views
Antimatter Explosion Signature
The DoomFleet returns!
And this time, it's with a more "Conventional" weapon - That is, projectiles with an antimatter core. Ultra-simple explanation is they have a "small" amount of antimatter in ...
10
votes
3
answers
581
views
How to fit three habitable worlds in our solar system?
Assume there are three earth-like worlds in our solar system. These three worlds would also have a single natural satellite roughly at the same mass-distance ratio of Earth to the Moon (about 1.2 ...
20
votes
4
answers
3k
views
How would other planets in a solar system be affected by the disappearance of one planet?
So let's say it's a big planet, like a Jupiter. Not talking about our Solar System. This is hypothetical. But say a Jupiter-esque planet in a solar system suddenly disappears. And by disappears I mean ...
5
votes
2
answers
2k
views
How would our sky look like 100 million years in the future?
Right, you are standing on Earth 100 million years in the future and observing the sky. What would you see during night and how would a day look like when you look up. Weather is not relevant (no ...
5
votes
5
answers
1k
views
If an immortal, fabricated particle could travel FTL, would it exist in all times, or only the past relative to its present?
This seemed too scifi or hypothetical for physics, so here goes.
Suppose a manipulated quark with 0 mass could travel faster than the speed of light. It's known that the faster you go, the slower ...
3
votes
2
answers
140
views
Sun/stars orbit and climate
I understand this is a broad topic that to a degree was answered in previous questions.
What I'm trying to do is to create a plugin in Unreal 4. I'll start by creating a day/night system and a ...
3
votes
3
answers
190
views
How to tell if a planet with twin suns orbits one or both of them?
An experienced space time traveler teleports from place to place and planet to planet with a vehicle or using psychic powers. Now suppose that this traveler teleports to a habitable planet.
Suppose ...
13
votes
4
answers
4k
views
Detecting a neutron star entering the solar system
In its wandering through the Milky Way, the solar system is getting close to a solitary neutron star.
The neutron star will "fly by" above the plane of the ecliptic and its closest distance from the ...
8
votes
4
answers
347
views
Detecting an Alien Civilization on a Nearby Planet
This question is inspired by NASA’s recent TRAPPIST-1 announcement. Imagine two planets orbiting a star with orbits very close together. At the nearest point in their respective orbits they are only 1 ...
24
votes
5
answers
2k
views
Is it safe to orbit HDE 226868?
I'm considering a story where an exploration is devised to explore a binary system containing a black hole; the choice is Cygnus X-1, with its companion supergiant star HDE 226868. It would likely be ...
-4
votes
3
answers
312
views
How massive of a foreign body going at near light-speed (>99.9999% C) would it take to make the sun explode?
It doesn't have to be a rock, in fact it would probably be depleted uranium or even some crazy material like neutronium.
3
votes
1
answer
104
views
Can an ocean moon with a mass of 0.5 earth masses stabilize the axial tilt of a planet two times bigger than earth?
The world will going to be the homeworld of an hairless feline humanoid race, but I want to see the plausibility of this scenario?
10
votes
5
answers
803
views
What useful materials exist on a lifeless planet?
Supposing you are trying to colonise planet that has no life what-so-ever but is otherwise an earth analogue.
First thing that I realised is that there would be no oil. So they would need to make ...
19
votes
4
answers
2k
views
Earth-like Moon around the Gas Giant. Eclipse length?
Worldbuilder in dire need!
I'm trying to figure out the eclipse length of a habitable Earth-like moon that is rotating around a gas giant. The story that I work on is centered on the Earth-like moon, ...
3
votes
7
answers
226
views
How to negate gravitational influence of specific objects in space?
The way the Earth travels is dependent on the gravitational influence of matter that surrounds it. This question is of how/if we can prevent or reduce certain objects effects on Earths movements ...