Questions tagged [orbital-mechanics]

The application of ballistics and celestial mechanics to the practical problems concerning the motion of rockets and other spacecraft.

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Explanation of an imaginary transformation occurring in the determination of trigonometric series for the elliptical equation of the center

One of the oldest problems in astronomy, which dates back to to the time of Kepler, is the problem of development in infinite trigonometric series of the "equation of the center" - to ...
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How would a retrograde satellite experiencing tidal deceleration affect the rotation of the primary?

There are two common scenarios like this one, where an orbiting body orbits its primary slower than the primary rotates, resulting in the orbiting body moving away and the primary experiencing a ...
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Apparent Centering Problem When Using the Perifocal System to Draw Orbital Ellipses [closed]

I am attempting to render orbital ellipses in software. Given a set of orbital elements, I am using the Perifocal system to determine a set of points along the curve of the ellipse. I am using the ...
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Does gravitational radiation change the eccentricity of binary orbits?

Do the eccentricity of a binary orbit change with change in the semimajor axis due to loss of orbital angular momentum by gravitational radiation?
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What meteor shower has the radiant that appears furthest west after sunset, and why?

When it finally gets answered, answers to How to calculate the position of a meteor shower's radiant point based on its associated comet's orbit? will help us understand why the radiant points ...
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Would a satellite that has a retrograde orbit and a shorter orbtial period than its planet's rotational period be tidally accelerated or decelerated?

There are 4 configurations to consider. A satellite orbiting a planet that: Has a prograde orbit and larger orbital period than its planet's rotational period (example: The Moon) Has a prograde ...
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Speculative Question Concerning the Planet Theia [closed]

I am a writer and I'm building a paradigm wherein the planet Theia did not strike the Earth, but settled into a orbit around the sun a third of the distance between the Earth and Mars. I wanted to ask ...
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How to calculate the position of a meteor shower's radiant point based on its associated comet's orbit?

Below this answer to Why are Delta Aquariids “for the southern hemisphere” while the Perseids are “for the north”? I wrote the comment: +1 To make this complete, ...
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What effects does the motion of the Sun have on the perihelion precession of Mercury?

According to the wikipedia page, there are multiple effects contributing to the perihelion precession of Mercury. Of course, according to this link and this link we know that the Sun is itself ...
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Closest stable orbit about the sun of an asteroid?

What is the closest perihelion an asteroid in stable orbit could have? Is there a limit defined by orbital mechanics or could an object be in stable orbit, only too close that melting or sublimation ...
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Comet Neowise c2020 f3 will return in ~6800 years, how can we be sure Earth will be in the right place to see it then?

I have read in several places that the orbital period of comet Neowise c2020 F3 is about 6800 years. In several popular media sources it is said that we will be able to see the same comet after ~6800 ...
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Why Comet C/2020 F3 Neowise returns even it's orbit is near- parabolic?

I have read in Wikipedia about Comet C/2020 F3 Neowise that it's orbit is near-parabolic. But in another section, it says that it is a non-periodic comet whlith orbital period ranging from 4500 years ...
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Can the paper narrowing Solar System's barycentre to within 100m help find Planet Nine?

I've just read this recent news article, Astronomers Have Located The Centre of The Solar System to Within 100 Metres, reporting on a paper[1] that claims narrowing the Solar System barycentre to ...
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What is the orbital velocity of Pluto around the Pluto-Charon barycenter?

I know the formula for orbital velocity but that doesn't seem of much help when I'm trying to calculate how fast the primary wobbles, or since the barycenter is outside Pluto in the Pluto-Charon ...
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Can I calculate the apparent position of comet NEOWISE C/2020 F3 from a topographic position with Skyfield?

I'd like to get .altaz(next_several_weeks) of this comet from Skyfield and .separation_from() other planets. It reads the JPL ...
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Hypothetical planet jump: Will it perturb star systems?

In a more speculative corner of SE somebody was dreaming up a story of planets traveling between star systems through wormholes. I was wondering how much the appearing/disappearing of a planet the ...
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Is the gravitational field of the sun uniform?

I understand that rocky bodies in the solar system all exhibit gravitational anomalies. Does the sun exhibit any gravitational anomalies? If so are they distinct enough that it effects the orbit of ...
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How to project an arbitrary elliptical orbit onto the night sky plane?

An ellipse E is arbitrarily oriented in 3-D space with the origin at one of its foci. Use the standard elements provided in the figure. Assume the reference direction $\gamma$ or $\gamma'$ is the ...
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How large were the deviations of Uranus's positon from predicted which led to the discovery of Neptune?

After Uranus was discovered and its orbit calculated, its future orbit was calculated, and its future positions as seen from Earth were calculated. And observers of Uranus began to notice that Uranus ...
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Why is the Moon's orbit so complicated?

I like to think I have a good enough understanding of astrophysics but there's still one thing that I just can't explain. Why does the Moon orbit the Earth the way it does? Many other moons in the ...
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Keplerian Elements for Approximate Positions of the Major Planets

Simple question here. I am working on something that needs to compute an orbital path using Keplerian Elements. When doing some research I came across this JPL page: Click Here. Within that link is a ...
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Understanding the JPL Ephemerides

I'm working on an animation that replicates our Solar System. I know this has been done before, but I'm working on something that requires me to make one myself. With that being said, I'm having a ...
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Why does the Parker Solar Probe slow down as the distance from the Sun increases?

Why does the Parker Solar Probe slow down as the distance from the Sun increases? Image credit: Wikipedia user Phoenix777, CC BY-SA 4.0
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Can you create an orbit in a space station using balls?

Would it be possible to spin a ball in a space station, and for it to create its own orbit for a smaller ball to rotate around it?
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What kind of triangle is formed by three unequal masses in a circular restricted three body orbit?

This answer to Are the orbits of all triple star systems at least technically unstable? mentions: There are known solutions to the gravitational three body problem that can be shown to be stable. ...
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Have meteor showers been predicted for planets or solar-system bodies other than Earth? Have attempts been made to detect them?

Per the linked Q's and A's in Why do particles from a comet that result in meteor showers spread out mostly along the comet's orbit? and it's answer, meteor showers happen on Earth when it passes ...
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Roughly what fraction of comet orbits that intersect Earths' orbit result in known meteor showers?

Per the linked Q's and A's in Why do particles from a comet that result in meteor showers spread out mostly along the comet's orbit? and it's answer, meteor showers happen on Earth when it passes ...
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Why do particles from a comet that result in meteor showers spread out mostly along the comet's orbit?

My understanding of the meteor showers that repeat yearly is that the Earth passes through the orbit of a comet that is nowhere near us, and might not even exist anymore, yet it's orbit is filled with ...
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Do Astronomers really never call Lagrangian points “libration points”?

In this answer to Who called the Lagrangian points as “Libration” points and and why was the terminology “Libration” used? I described my feeling that Lagrangian points were also sometimes called &...
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Is the vernal equinox always in zenith somewhere on the equator?

I'm trying to visualize the satellit orbital parameter "right ascension of the ascending node" (RAAN). Measuring the angle from the vernal equinox to the point where the satellite's orbit crosses ...
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Why does the closest approach of star S2 to Sgr A* not appear to be near the focus of its elliptical orbit?

Phys.org's Very Large Telescope sees star dance around supermassive black hole, proves Einstein right links to several ESO videos, including The star S2 makes a close approach to the black hole at the ...
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What was that single file line formation of flashing plane lights flying in the sky at night? [duplicate]

It was here on the west coast at 5 am pacific standard time when I went outside for a smoke when out of the corner of my eye what looks like a plane with flashing lights going across the sky when all ...
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Comparing orbits between a planet and Red Dwarf

I have a MATLAB problem, so I have an earth like planet orbiting around a sun like star and then there is a red dwarf on an elliptical orbit around the star that passes close to the planet. I want to ...
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Is this a potential planetary setup for the Alpha Centauri System?

I originally posted this on the World Building SE, but I was suggested to post it here for a better answer. I am attempting to create a [semi]plausible star system in Alpha Centauri for a series. The ...
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Determining the area of Lagrange Points

I have looked into Lagrange points a decent amount and I see many images that show the L4 and L5 locations as wide sweeping areas. Jupiter's Trojan asteroids are a good example of this. As well, L3 ...
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Planetary phase angle of Hohmann transfer

This is Question 23 from USAAAO First Round 2015. The answer is D. Can someone show how to get the answer? Calculate the planetary phase angle (counterclockwise from Earth, a = 1.0 AU) that a probe ...
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Combined mass of binary stars

This is Question 17 from USAAAO Practice Round 2015. The answer is D. It would be best if someone can detail out the workings. In a nearby star system, two stars are seen to orbit each other every ...
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How close would the sun have to get to a supermassive black hole to have Jupiter stripped and slingshot into interstellar space?

Please make whatever assumptions are needed. Assume sun approaches black hole on some sort of hyperbolic trajectory. Assume size of supermassive black hole is same as the one at center of our galaxy....
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Is a year really 365.24 days, or is it 365.2564 days like I remember?

The NPR News item and podcast Spring Starts Today All Over America, Which Is Weird includes the following: But why isn't the time of the equinox the same each year? The short answer is that the time ...
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Why are asteroids with zero orbital inclination rare?

This is a plot of orbital inclination ($i_p$) vs. semi-major axis ($a_p$) of 96944 asteroids in the Main Belt, done by Piotr Deuar. Some structure can be seen in this diagram; clumps are asteroidal ...
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How feasible would it be to get to a planet orbiting directly opposite Earth?

Imagine that in addition to Earth, there was a second planet, say of one Earth mass, orbiting the sun - but on the opposite side of the Sun, and at the same orbital radius. My question is - given ...
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Binary star system effects at the barycenter

I haven't been able to find anything on this so far. Using Alpha Centauri as the study, what events/effects ( if any ) would happen between the two stars? More specifically, between the gravitational ...
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Binary planet orbital distance

From reading various sources online, I see that some people talk about binary planets in very tight orbits (around 1 or 2 planet radii). I am wondering if it is possible for a binary planet (Double ...
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Why is there no concavity in the orbit of the moon around the Sun?

Such questions have been asked here and I have read the answers some of which are quite informative. However, I want an answer that's straightforward. I have gone through the following paper by A B ...
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How is the Sun tilted to its orbit around the Milky Way's center?

We know how the Sun is tilted in reference to its planets but how is it tilted to Sagittarius A or its orbit around it? Or isn't it tilted at all?
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Why is the asteroid belt shaped like a triangle?

So, in this question, the user JollyJoker posted this image depicting the orbits of the asteroids in the asteroid field in the comments: [ In this image, you can see that while the individual ...
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What would happen if the earth's orbit were slightly perturbed?

Suppose a rogue planet came zipping through the solar system and changed the earth's orbit a little, including the plane of the orbit. I have the idea that, in a complex system, orbits would tend ...
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Is there a verification of the solar system barycenter as it is theoretically determined?

The barycenter of our solar system is not the sun, but a changeable location outside of the center point of the sun. A often used diagram of that relation is shown below, originated from the Wikipedia ...
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What is the cycle for when the maximum amount of the Moon's apparent area is sunlit?

The Moon is defined as full when its ecliptic longitude is 180$^{\circ}$ distant from the Sun's. But what is the cycle for when the maximum proportion of the moon's apparent area is sunlit, and for ...
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Kepler's equation and eccentric anomaly

From the wiki article about eccentric anomaly follows: $$\cos E = \frac{x}{a}$$ $$\sin E = \frac{y}{b}$$ where E - eccentric anomaly, a - semi-major axis, b - semi-minor axis, P = P(x,y) a point on ...