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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61 views

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 ...
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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 ...
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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 ...
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Scientific possibility of stationary moons for a writer of fiction

I tried to do some research to find an answer for this question before posting this but didn't find anything that I could sink my teeth into. I was wondering: if it would be possible for a planet to ...
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Can Kepler's 3rd Law be applied in higher dimensions to describe orbits (quadric surfaces)?

Motivation for asking: The 2-D orbital path of a celestial body revolving around another celestial body due to the force of gravity can be described by a conic section; this is the curve formed by ...
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In binary systems, does the speed of the objects vary as they adjust to the movement of the other object?

The speed of objects orbiting in a binary system, like Pluto and Charon, is the speed and direction of the objects smooth, or, do the objects make adjustments that are in some ways like a "tug of war" ...
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Do planets orbit the sun in ellipses because of sun movement vector?

The assumption is made that the planets of our solar system all have elliptical orbits elongated in the same direction. Further, generalized to that orbits around any object with its own orbital ...
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Could the barycenter orbit of our sun be greatly underestimated?

The radius of the suns orbit around the barycenter of the solar system is often measured to be roughly the radius of the sun. Based on the same type of bias that has made humans miss things about ...
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Could a gas giant orbit a star with a 30 year period at a distance of just 1 AU?

Assuming a star with similar properties to our sun, could a gas giant orbit it with an orbital period similar to that of Saturn, but, at a much closer orbital distance, more similar to 1 AU?
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How do I calculate the Hill radius of a star in a binary system?

Is there an easy way to calculate the Hill radius of a star in a binary system at different orbital radii where both stars are of the same mass and in circular orbit around one another’s centre of ...
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Is Earth's Surface “In orbit”?

I'm having trouble understanding relative angular/tangential speeds at increasing altitudes above Earth's surface. In particular, I find this comparison of tangential velocities on Wikipedia very ...
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What exactly is the relationship between the orbits of Neptune's moons Naiad and Thalassa?

Scitechdaily's Wild Orbits of Neptune Moons a ‘Dance of Avoidance’ [Video] links to the YouTube video Neptune Moon Dance (Naiad and Thalassa) and says: In this perpetual choreography, Naiad swirls ...
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Are the orbits of all triple star systems at least technically unstable?

Background: In the Circular Restricted Three Body Problem (CR3BP, CRTBP) some halo orbits are mathematically stable. That means that the orbit of the third body is closed, periodic, and stable ...
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How to find the Orbital Period of two Binary Planets around a Single Star?

This is kind of a weird one. Bare with me! :) Background: (Skip to the math below if you just want to answer questions) In my favorite game, Elite: Dangerous, I "own", or occupy I guess, a system ...
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Given that Kepler's Third Law as stated on most websites doesn't include mass, how does it work for planets in other star systems? [duplicate]

Kepler's Third Law as stated on websites I found while searching for "how to convert between a planet's orbital period and semi major axis" is $P^2 = A^3$ where P is the orbital period in years and A ...
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Orbital speed is (vector) sum of tangential and normal speed?

Orbital speed definition in wiki does not state clearly - it is just tangential speed component or square root of squares of normal and tangential speed (full speed vector). When we say that moon ...
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Could someone please explain to me how I can extract velocity component values from Stellarium, for a given planet?

For a project that I am currently working on, I would like to know how one could extract velocity component values ($v_x$, $v_y$ and $v_z$) for a planet from the Stellarium software. The current ...
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Would an object shot from earth fall into the sun?

Would an object shot from earth fall into the sun? If an object is shot at 107,000 km/h via rocket or otherwise, in the opposite direction to our orbit about the sun, it will be traveling at 0 km/h ...
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Propagate Earth trajectory for 1 Myr

What is the most accurate way of propagation of Earth trajectory relatively to the Sun? I need to calculate the Earth-Sun distance. Is there any library on Python? I've used before JPL Horizons, ...
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Would two Earth-like planets on opposite sides of a Sol-like star at about 1 AU be a stable configuration?

Would two Earth-like planets on opposite sides of a Sol-like star at about 1 AU be a relatively stable configuration? I understand that there are tadpole-like orbits and the two planets may not stay ...
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Change of orbit with change of mass?

In the science fiction book 2010, monoliths increase the mass of Jupiter until it becomes a star. https://en.wikipedia.org/wiki/2010:_Odyssey_Two The Leonov crew flees Jupiter as a mysterious dark ...
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Origins and most frequently used; perinigricon vs peribothron?

Gizmodo.com's Astronomers Spot Unprecedented Flashes From Our Galaxy's Black Hole mentions Sgr A*'s companion gas cloud G2 and that Wikipedia article uses the term perinigricon, but that mentions ...
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How does the orbit of a 2-body system evolve as it orbits a more massive 3rd body?

I have been reading up on how multiplicity of star systems decline with star mass, which implies a relatively common occurrence of binary star systems orbiting more massive stars. I would imagine this ...
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Speed of Moonrise relative to fixed point on ground

Due to the curvature of the earth, and the way the moon interacts with the atmosphere (especially close to the horizon), is there a known function that describes the speed of the moon relative to its ...
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How do a planet's moons and a planet's rings interact?

I am making a video game which features a planet and its moon. And I thought I would add rings too. But that got me wondering... how do a planet's moon and a planet's ring influence each other? Does ...
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periodic inclination change circumbinary planet

I am studying circumbinary planets and I made a python model to calculate certain properties of the orbits, and when I calculate the inclination I get a sine wave. I do not see a way to predict the ...
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Can Eight Retrograde (seen from Earth) planets occur?

First of all, for the purposes of this question Pluto is a planet. So the eight planets being considered are Mercury, Venus, Mars, Jupter, Saturn, Uranus, Neptune and Pluto. My question is: can all ...
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What kind of effects can maintain Uranus' rings' eccentricities?

The recent paper Thermal Emission from the Uranian Ring System has been in the news recently. The introduction mentions: The ε ring, the brightest and most massive of the narrow rings, was shown to ...
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How can the oblateness of Earth impart torque to change the longitude of ascending node of a satellite?

I've read that you can change the longitude of ascending node of a satellite (i.e. changing the orbital plane without changing the inclination) to change its orbital plane by using the torque imparted ...
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Calculation of day lengths of moons or moons of moons

Is it possible to calculate the day lengths of moons or moons of moons? If so, does the day length depend on the longitude as well as the latitude? Also, if we calculate the day length, is it possible ...
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Why isn't Earth tidally locked to the sun?

Given that the moon has long been tidally locked with the Earth, why isn't Earth (or any of our other solar system's planets) tidally locked to the sun?
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How to choose between methods to resample/interpolate ephemeris state vectors? Are there recognized techniques for orbital data?

I have ephemeris data for state vectors of a satellite in a J2000.0 coordinate system. This data is already filtered and cleaned. The data sample rate ranges between 1 second and 60 seconds, and I ...
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How was this interstellar fireball observed and its trajectory analyzed?

The short, interesting paper Discovery of a Meteor of Interstellar Origin describes a proposed discovery of a second interstellar object. This one hit the Earth, and was discovered not by telescope, ...
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How to determine the eccentricity, knowing the orbital speed and distance

How to determine the orbital eccentricity of a planet, knowing the instantaneous orbital speed of it and the distance from the Sun to the planet at that moment?
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What is the force that changes a satellite’s inclination when orbiting a planet with an equatorial bulge

I tried looking this up without success and I imagine there's a formula for it, with some ridiculous numbers like it drops off to the 5th power of the distance or maybe even more. Imagine a planet ...
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How to draw an orbit from Orbital Elements using Transform3DGroup

I am trying to draw an orbit using the Transform3DGroup class in the C# .NET framework. I have orbital elements a, e, i, RAAN, ArgPer, trueAnom. The algorithm that spits these out for me also gives me ...