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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Do there exist open-source implementations of non-SGP4 propagators?
I'm well familiar with SGP4 and its implementations in various languages. I am curious if there are open-source implementations of J2Mean, J2, J3, J4, etc propagation techniques.
If my terminology is ...
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How quickly would these changes happen if the moon were to suddenly disappear?
There's a lot of articles and videos on the topic of what would happen if the moon were to suddenly disappear. Two consequences that seem to come up often are an increase in variation of Earth's axial ...
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Basics of Tracklet-less Heliocentric Orbit Recovery (THOR) - simple breakdown of how it works?
The New York Times's April 30, 2024 Killer Asteroid Hunters Spot 27,500 Overlooked Space Rocks begins:
With the help of Google Cloud, scientists churned through hundreds of thousands of images of the ...
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Could a planet or its moon be synchronously tidally locked with the sun, but still in orbit with its moon/planet?
Obviously, with so many stars and presumable planets, lots of things can happen for a short time, but I'm wondering if there is a stable configuration for either twin planets or a planet with a ...
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Would a planet's tidal forces really push away a moon out of its Hill Sphere?
If a moon orbits in the same direction as its planet's rotation (i.e. a prograde orbit), and its orbital period is longer than its planet's rotational period, then tidal forces would cause the moon to ...
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What can be learned from viewing the sun on earth during a total eclipse that cannot be studied by spacecraft in orbit?
I understand that total eclipses are a fantastic time to study the sun's corona, and the reason for this is because the much brighter photosphere is blocked by the moon. But, couldn't the Parker solar ...
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Relative translational dynamics of two spacecraft in Keplerian orbit
I need your help understanding some equations in a paper about autonomous rendezvous and proximity operation. The paper is available at this link, but I will summarize the main point in the following.
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Has anyone attributed a specific Baily's bead to a specific feature on the Moon? If so, when was this first done?
From Wikipedia's Baily's beads:
Lunar topography has considerable relief because of the presence of mountains, craters, valleys and other topographical features. The irregularities of the lunar limb ...
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Is the Moon really oscillating around its orbit as seen from Earth?
While simulating today's eclipse, I see something I have never noticed or learnt:
Stellarium shows an oscillation of the Moon's trajectory around its orbit as seen from Earth.
Is it real or a ...
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How can I plot a rotary cam for the equation of time? [closed]
I'd like to use Solidworks to create a cam (peanut looking) for computing the equation of time in a pocket watch. Would appreciate any point to the right direction or advice.
Audemars Piguet EoT
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Finding the cartesian position of the lunar ascending node
What I'm trying to derive
The cartesian position of the lunar ascending node relative to the true equator and equinox of date reference frame. My issue is I'm getting a bit tripped up with reference ...
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How can Earth-Sun Lagrange points L1 & L2 even be semi stable considering the moon?
I know that the Earth-Sun Lagrange L1, L2, and L3 points are not considered stable over longer periods, especially when compared to L4 and L5... But, with the moon orbiting the Earth in the general ...
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Is this description of ecliptic times correct?
I did a brief write-up as a pet research project to explore astro-geological calculation and visualisation for
Muslim prayer times. It's not meant to be authoritative (either scientifically
or ...
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Converting equatorial coordinates of a comet's pole into cometocentric orbital coordinates I and Phi
The comet's spin axis orientation is usually reported in equatorial coordinates RA, Dec; however sometimes these are shown in form of the Eulerian angles equatorial obliquity (I), i.e. the angle ...
VIRGINIO OLDANI
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Area of Influence of Lagrange points?
By which I mean, the area around a Lagrange point where the linear-force approximation of the 3-body system defined at the Lagrange point itself is "good".
Background
Consider the restricted ...
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How well are planetary formation models (e.g., determining $\mathrm{\dot{M}_{planet}}$) understood in 2024?
I know that planets can form through accretion, bulging up from $0$ to their final mass $\mathrm{M_{planet}}$ at $\mathrm{M}(t_f)$. I know that when studying Planetary formation and migration theories,...
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Is it coincidence that the earth's rotation and revolution are in the same direction?
In a reference system where the sun is static, the rotation and revolution of the earth are, when viewed from above the north pole, both counterclockwise.
Is it a coincidence that they agree? Or does ...
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Fractal structure of the universe
I decided to return to the question first written here after some time, since a short and succinct phrase had formed in my head that described the phenomenon that I was trying to understand.
What are ...
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Will the Moon recede far enough that the Earth-Moon barycenter lies outside of Earth's radius before the Sun becomes a red giant?
As most people know, the Moon is receding from Earth at a rate of a few centimeters per year. This rate is not constant; as the Moon gets farther away, the tides it raises will be weaker and thus will ...
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Corkscrew-like stable two-body system
I recently created a celestial body simulation in python for one of my classes. While playing around with different values I obtained a weird two-body stable system.. For context, these bodies are ...
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Would the Earth still precess if it were an ideal sphere?
Migrated from Space Exploration
I am trying (unsuccessfully) to acquire an intuitive understanding of planetary precession.
Is Earth’s precession Torque-free Precession due to its asymmetry as per ...
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Equation for calculating boolean answer to "is this Earth satellite in eclipse"
I have found plenty of math for determining duration of satellite eclipse, but I am having trouble finding an equation that produces a simple boolean answer to the question "Is this Earth ...
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Are there mascons on Ganymede similar to the ones on the Moon? And if so, how will that impact JUICE when it orbits over Ganymede?
Mascons, also known as mass concentrations, are anomalous features on the Moon that tug on orbiting spacecraft and cause their orbits to decay and crash on short timescales. There are only a handful ...
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Do moons of rocky oblate planets migrate to low inclination over time? If so, does the time it takes depend on the Moon's size?
Discussions elsewhere suggest that this happens and that smaller moons would tend to low inclination with respect to the planet's equator faster than larger ones.
For example, Mars' small moons are ...
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Just how resonant is the "resonant sextuplet of sub-Neptunes transiting the bright star HD 110067"?
The November 29, 2023 arXiv preprint A resonant sextuplet of sub-Neptunes transiting the bright star HD 110067 constructs a resonant chain of orbital periods based on mean motion resonances (MMRs) and ...
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Do the Galilean moons' orbits around the Sun have loops (i.e. have concave parts)? And if so, how can their orbits be graphed?
The shape of the Moon's orbit around the Sun has been discussed to death, and the answer is that the Moon's orbit has no concave "loops" whatsoever.
I am relatively sure that the determinant ...
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Appropriate NEO databases for preliminary orbit determination simulations
I am a high school student that is currently writing an extended essay in physics. In my essay I compare the accuracy of Gauss method and double-r iteration method for determining the preliminary ...
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Should you include aberration effects during low Earth orbit observations?
I am working on calibration of some observations of low Earth orbit satellites and I am wondering should I include aberration effects? My logic is that diurnal aberration would have neglegible ...
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Hierarchy of gravitational interactions of astronomical objects: from single to large-scale structures
Hierarchical structure is clearly visible in the Universe. The "observable universe" includes almost empty voids, between which lie large cosmic filaments. The filaments consist of galactic ...
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Three Body Problem using Python
I need help with an assignment. I'm doing a little project for a subject on my university and as the title says, its to find a solution to the three body problem restricted to a circular motion.
The ...
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Which star system has the highest multiplicity (# of stars), whose orbits are known for all stars?
I posed a question on here a couple months or so ago about the orbital patterns of each of the seven stars in the two septuple star systems Nu Scorpii and AR Cassiopeiae. It went unanswered for more ...
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How do the orbits of star systems V871 Centauri (septuple), Gamma Cassiopeiae (octuple), and QZ Carinae (nonuple) work?
Several years ago, I asked the question on here, "How do the orbits of Nu Scorpii and AR Cassiopeiae work?" At the time, these two stellar systems were the most populated (I don't know the ...
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Is the motion of Mercury circular when viewed from Earth?
If observed from Earth, the Sun appears to move in an approximate circular orbit. For the motion of another planet like Mercury if observed from the earth, would this be true? If not, why? What about ...
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How to translate from local laplace plane to ecliptic J2000 (or ICRF)
The NASA JPL websize gives mean orbital elements for e.g. Iapetus or Titan in relation to the local laplace plane.
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Apsidal precession
I found this article about calculating apsidal precession:
https://farside.ph.utexas.edu/teaching/336k/Newton/node115.html
I tried to calculate rate of apsidal precession from this equation, but I had ...
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Orbit of the moon so that there are no eclipses
Theoretically speaking, what orbit should the earth's moon must take so that there are never any eclipses - solar or lunar? Is it mathematically possible to construct such an orbit?
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Are there any bodies in the solar system whose rotation is almost tidally locked or barely tidally locked?
The Moon's rotation is firmly tidally locked to the Earth and the Earth's rotation is firmly tidally unlocked with respect to the Moon. I gather that Mercury's rotation is tidally locked in a 3:2 ...
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How to convert TEME (or ITRF) to horizontal
I have TEME coordinates from sgp4 propagation. I can convert those (in python) to ITRF given date and time of observation. How to convert coordinates from one of those two frames to horizontal azimuth ...
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What are "non-Keplerian" orbits? What are some familiar examples in our solar system, and can some still be closed?
This excellent answer to Forms of stellar orbits around the galactic center invokes the following concepts:
non-Keplerian orbits
closed orbits
I have a fairly good idea what these mean and so might ...
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Are dust-dust collisions necessary to explain Kordylewski clouds at Earth-Moon L4/5? Aren't the cross-sections, number density timescales too small?
The recent question Can dark matter accumulate at Lagrange points? mentions Kordylewski clouds and that article begins:
Kordylewski clouds are large concentrations of dust that exist at the L4 and L5 ...
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Under which conditions could a planet's massive moon's orbit get closer to the planet?
The recent question How do we know the Moon was much closer than it is now? has piqued my interest. The answers are numerous and clear. But I started to wonder. The question includes the following ...
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How to turn find velocity dispersion from radial velocity
In the above given picture Vi is the velocity of the i-th galaxy in the cluster while Vm is the mean velocity of a galaxy in the cluster. and V i,r is the radial velocity of the i-th galaxy and V m,r ...
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Concerning a binary system of stars/planets/black holes could one of them be ejected before eventually merging or colliding?
I was having a discussion with an undergraduate student of physics about binaries and their interactions with external celestial bodies (which could cause the ejection of one of the members in the ...
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Gravitational recoil with stars/planets...?
When two black holes are merging, the resulting merge can be ejected if one of the black holes had less mass than the other one, so the gravitational waves emitted by both of them is unbalanced, and ...
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Eccentricity of TLE orbit from velocity and radius in TEME
I was reading this question: Calculation of Eccentricity of orbit from velocity and radius and tried to use the proposed equation to reconstruct the ecco field of TLE by it's R,V vectors. The formula ...
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Will all satellites get inevitably tidally locked to their planet?
Are there cases or conditions in which an object orbiting another one (e.g. a satellite and its planet) does not get tidally locked to it?
For example, in this question, it is mentioned that a large ...
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Can rings last around planets indefinitely?
Apparently, Saturn is losing its rings (https://weather.com/en-IN/india/space/news/2023-05-04-saturn-is-losing-its-rings-webb-may-tell-us-how-long-they-have-left) However, is there any way or ...
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Can a solar system exist where the second planet rotates fast, and the third planet is tidally locked to their star?
Today I read about the Romulan home star system and it looks like it might be impossible for such a star system to exist.
Memory Alpha describes Remus:
Remus was tidally locked, with one ...
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What is the shape of orbit assuming gravity does not depend on distance?
We know that the orbit of the earth is elliptical considering the force of gravity is inversely proportional to the square of the distance. But assume that, gravity does not depend on distance. ...
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Do all orbits emit gravitational waves?
In principle, all orbits in the universe should progressively decay due to the emission of gravitational waves. However, does this always happen? Are there any kind of orbits that do not decay as they ...
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