Questions tagged [astrophysics]
For questions regarding the application of the laws of physics to orbital mechanics, stellar evolution, and other astronomical processes and celestial bodies.
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If Earth were located at 1.1 AU from the Sun, would this affect the two zenithal passage days in the Tropics?
I am designing calendrics for an Earth-like planet located 1.1 AU from a Sun-like star. On Earth, on April 30th and August 13th, the Sun appears to pass directly overhead between the Tropics of Cancer ...
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Could a captured planet end up in the habitable zone of a new star system?
Is it possible for a planet to be ejected from one star system and end up in the habitable zone of another? Or do captured planets always end up in wide, eccentric orbits?
I guess in the vast expanse ...
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Could a planetary object spin at (or near )the speed of light? [closed]
And if so, what would it look like to an observer on the planet and an observer in orbit around the planet?
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What would happen to an Earth-like planet if it had a more magnetically permeable inner core?
I was contemplating the impact of doping an Earth-like planet's core with a substance that alters its magnetic permeability. Specifically, I considered a scenario where the planet has an improved ...
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Looking for a Specific Planet
I know my title isn't the most specific, but the planet I am looking for is. I have been looking through many exoplanets and I can't seem to find what I am looking for, the closest I have found is ...
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Could a slow rotating planet combined with high density atmosphere create high winds?
I am trying to design an alien ecosystem around a K type star. My idea was to have purple plants and high wind atmosphere so originally I wanted to make it tidally locked. However after watching some ...
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How large should my supermassive planet's core be to prevent it from becoming a star?
My planet is a gas giant, it is called Klarloth (Inspired by a character from "Star Mouse" by Fredric Brown).
Klarloth is a strange planet. For one thing, the planet is large in size, more ...
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Stopping Milkdromeda, for Aesthetic Reasons
Basically, there is a human civilization controlling the milky-way and an alien civilization controlling Andromeda. They are communicating and have decided, for some reason, that, though the ...
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Calculating distance of the frost- and ice line
To begin, my star is a K type star with 0.65 solar masses.
I've inserted my star's mass in two different templates to calculate the frost line, yielding different results (2 AU and 2.68 AU).
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Would a planet with a retrograde spin function as if it were spinning faster or slower?
I am thinking in terms of the Coriolis Effect, atmospheric circulation and specifically Hadley Cell latitudinal width here, but the base question still stands.
For ease of reference, if we take a ...
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How many giant planets could form in a hierarchical triple star system?
The system in question has a very close binary pair of 2 G-type stars, a G9V and a G7V, orbiting at about 0.2 AU, with a K2V star in a far orbit about 300 AU out around the both of them. There is a ...
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Exotic life in a brown dwarf
From what I have seen in the discussions here about possible life on brown dwarfs, it’s concluded that no complex chemical life (even metallic or CNT based ones) can survive the radiation and gravity ...
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What stellar temperature, orbital distance, and eccentricity is needed to create an Earthlike orbital planet with a last glacial maximum climate?
I am creating an Earthlike planet with a year length of 515 Earth days and 9 Earth hours. I am aware that Kepler's third law of planetary motion states that warmer stars are needed for longer orbital ...
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How fast would this astronomical macromorph be?
I’m taking inspiration from Robert A. Freitas Jr.’s theory about alien metabolisms based on gravity rather than electromagnetism. He imagines astronomically sized beings that derive energy by ...
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KBC Void Stupendously Massive "Vacuum Hydrogen" generators- How to convert the Anti-Hydrogen into Hydrogen?
So, let me get this straight right here.
According to Wikipedia:
"The KBC Void (or Local Hole) is an immense, comparatively empty
region of space,...... The underdensity is proposed to be ...
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Alternate universe where life is more common; is it feasible?
Let's imagine a story where the "aliens" leave a lot of super-advanced technology somewhere in the solar system. Scientists spend years excavating this technology and while it seems too ...
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What are the repercussions of two asteroids in the asteroid belt colliding?
As the title states, what would happen if two asteroids in the asteroid belt were to collide? Specifically, two the size of 45 Eugina impacting with each other. In my story, I am thinking about having ...
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Practicality of building a space station in the tail of a comet
In my novel, I want to feature a large (>5km) centrifuge space station that was built on/into a comet, and is in the comet’s tail whenever it passes close to the sun. It is home to many criminal ...
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How stable would partial planetary rings be on Lagrange points?
Context
There's a comparison to what I'm talking about on a larger scale: Jupiter's got its Trojans and Greeks, and Earth does have them too. Those are more or less loose and sparse groups of ...
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What dictates whether an orbit gets disrupted or stabilised due to an orbital resonance?
Context:
I've got an asteroid belt analogue situated between a Gas giant and a Super-earth. I knew about resonances, so I started calculating them and placing some of them in the belt, especially ones ...
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What is the difference in speed between my two moons?
The planet in my current project is orbited by two moons, which like Mars' are relatively small and irregularly shaped. The largest moon orbits closer to the planet and the smaller one orbits farther ...
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Jupiter's moon Europa - is it possible to colonize Europa? [closed]
So basically, I have to write a thesis paper because I'm in the last year of high school. It is an independent research project and the culminating work of my studies in school, so it represents my ...
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Any way of having a breathable atmosphere with zero gravity in free space?(and universal directionality?)
Inspiration
This is heavily inspired by sunless skies in that sunless skies' world allows for the use of steam engines as space ship- equivalent (using steam jets as thrusters, while still able to ...
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How would these characteristics of a habitable planet in a triple star system affect the needed aspects of having two moons?
If a habitable planet is in a hierarchical triple star system (not unlike alpha Centauri) and has two moons but has a large torrid zone, what characteristics would my moons need to have in terms of ...
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433 Eros hits the Moon. How much rock hits the Earth?
A la this image I made.
The "how" (nuclear pulse drive "adjusting" Eros's orbit at its aphelion) and "why" (uber-sized Rods from God) isn't particularly relevant — all ...
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Effects on gravity on close binary planets
Let's say there's 2 planets orbit eachother as close as possible so they're oval shaped but not close enough to reach the roche's limit and be pulled apart. How would gravity be affected on the ...
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Can I warm up outer space?
My universe was created without stars, of any kind (which includes the sun!), and has continued that way for about 2000 years. To clarify, all life (intelligent life) was created by the deities around ...
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If someone blew up mars, how screwed is earth?
Mars has a gravitational binding energy of ~5x10^30 jouleS. If a bomb went off on mars that released that much energy, how much danger would the earth be in. Additionally, would debris striking earth ...
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How can we prevent the Earth being scorched and swallowed as the Sun grows and eventually enters its red giant phase?
The Sun is slowly growing more and more luminous.
As a result of these processes, multicellular life forms may be extinct in about 800 million years, and eukaryotes in 1.3 billion years, leaving only ...
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Would two people standing on opposite sides of a flat world be able to see the same constellations?
Quick drawing illustrating what I mean:
Two people (humanoids, between 1 and 2 metres tall) are standing on the ends (less than 1km from the edge) of opposite faces of a flat world (approximately ...
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Tides on a tidally locked planet
Picture the classic Earth-like tidally locked planet, with a frozen dark side, a boiling stormy light side, and a thin strip of habitable land along the terminator. The planet is similar in size and ...
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How would a planet with three suns, orbiting only one work?
Okay, I am planning to make a planet that has three suns, and orbits one of them. Each of the suns has its own orbital path, so it's possible for the planet to have one sun, two suns, or three suns in ...
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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 ...
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What is mathematical formula for finding the mean surface temperature on a planet in our solar system?
This question is to assume the common solar luminosity of approx $4 \times 10^{26}$ Watts.
The mean flux of Earth at, for example, 1.1 AU would be about 1176 watts--but how can I calculate mean ...
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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....
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Obliterating the Earth, *without* throwing rocks? [closed]
In this case, I don't mean "make the Earth uninhabitable", I mean "make the Earth a debris field". This has been asked before, of course, but the answers always seem be be some ...
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How large can the main disk of spiral galaxies get? [closed]
I'm asking how large (by which specifically I mean diameter in light-years, though a rough estimate of the number of stars would be appreciated) can the main body of the spiral galaxy get.
I'm ...
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Dealing with extreme heat and pressure in an underground colony on Venus
A colony has been constructed by robots for human habitation deep under the surface of Venus. They are totally sealed off from the surface, and the galaxy beyond, and live like a ship in a bottle
What ...
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How long would Earth be habitable after being knocked out of orbit? [duplicate]
Let’s say a rogue planet or something came close enough to Earth to knock it out of its orbit. Whatever event causes this, can this happen without disrupting human life in the short term and how long ...
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How would a spaceship not affected by gravity navigate between planets?
Presume there exists a metal called X-matter that has all the properties of steel, except it is repulsed by normal-matter instead of attracted. (For instance, a block of it would accelerate 9.81 m/s/s ...
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Galactic 'geographic' features, how could they impact galactic colonization efforts?
I have been wondering how galactic features could impact interstellar civilizations in the process of colonizing a galaxy (either andromeda or the milky way).
According to this video these features, ...
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What are the effects of Increasing the gravity on Mars?
I'm interested in the Physics around increasing the gravity of Mars to make it habitable. I was unsure how to work out what gravity would be needed to retain an atmosphere thick enough to hold liquid ...
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How to place multiple small moons and one large moon in stable orbit around an earthlike planet?
Earth has one very large, spherical moon believed to have been formed by a giant impact. Mars has two small, sorta potato-ical moons believed to have been captured. Suppose an otherwise earthlike ...
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Can moon people generate electricity using a gravity dynamo that is turned by the gravity of their host planet?
On Earth, we generate electricity from the Moon's orbit using tidal turbines. Would it be possible for denizens of the Moon to generate electricity using the Earth's gravity, using a windmill-sized ...
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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 ...
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How would a high escape velocity effect conditions on a low gravity Birch planet?
A birch planet is a theoretical far future Giga-structure where a shell world is built around a supermassive blackhole. I have been playing around with different astrophysical calculators to find out ...
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What kind of atmospheric composition would make the sky look green and still be breathable?
In my story scientists discovered a planet that look green from the telescope and they used a advanced starship to go there and the y found out that the planet is habitable with a breathable ...
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What would happen if a neutron star approached the solar system?
Given its enormous eletromagnetic field and gravity( and probably gravitational waves would be very powerful) what would happen if a neutron star approached Earth? What if approached just by few light ...
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Day/night cycle and tracking celestial positions in S-type binary star system
I know this has been asked before but I'm going to pose the question again under slightly different circumstances and with a more specific goal. I'm trying to work out the details of how the day/night ...
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Could a molecular cloud turn the Sun into a killer star?
Let's say an unknown cloud enters the Solar System and begins manipulating the Sun, destabilizing the magnetic fields. Could it end up causing the Sun to emit gamma ray bursts to render the system ...
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