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1
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2answers
113 views

Finding sphere of influence in multibody system

I would like to draw a boundary illustrating the sphere of influence of each body in a 3 body system. What is the best way to find such a boundary? My understanding is at the edge an SoI is the ...
2
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1answer
33 views

Coexistence at Lagrange points

I was wondering how precise the location of an object in a Lagrange point needs to be to maintain stability, since it seems that several natural objects (asteroids) exists together in some of these ...
1
vote
1answer
82 views

Determing Velocity of Moons

I have a question that I believe is relatively easy to answer, I am working on an $N$-body simulation of a fictional star system and am having trouble finding the velocity of moons so that they will ...
6
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0answers
298 views

Why is the orbital resonance of the Galilean moons stable?

It is well known that the orbits of Ganymede, Europa and Io are in a 4:2:1 resonance. Most online sources (including but not limited to Wikipedia) say that such an orbital resonance, along with the ...
3
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0answers
31 views

Why does planetary spin affect the stability of orbits?

Reading about the Hill Sphere I notice that "the region of stability for retrograde orbits at a large distance from the primary, is larger than the region for prograde orbits at a large distance from ...
3
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0answers
139 views

Isn't the Jacobi constant just the Lagrangian times 2?

At this wikipedia page the Jacobi constant is expressed as: $$C_J=2\left(\frac{v^2}{2}-U\right)$$ where $U$ is the potential energy and $v$ is velocity. If kinetic energy $T$ is defined (as it ...
3
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0answers
240 views

Simple model of the solar system. Parameters? Accuracy?

I was thinking of making a simple 2D model of the solar system, with planets moving along ellipses like $$x(t) = k_x \sin(t + k_t) (\sin(k_\phi) + \cos(k_\phi))$$ $$y(t) = k_y \cos(t + k_t) ...
3
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0answers
201 views

Calculation of a Gravity Resonance Keyhole

Can anyone describe the mathematics behind the calculation of a resonance keyhole (for a two-body model)? It seems like the size and position of the keyhole should be a function only of mass and ...
2
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0answers
64 views

What is the difference between Saddle points and Lagrangian points between Earth and the Sun?

I am studying MOND bubble effects in the Solar System (Paper). In "mond habitats.." (last reference) first page, the author says MOND bubbles reside on the saddle points but I fail to understand the ...
2
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0answers
165 views

Story about a mathematician, a dinner party, and the three-body problem

I remember dimly hearing a story, coincidentally also at a dinner party, and I was trying recently to track the details down with no success. I was hoping someone here might have also heard this story ...
2
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0answers
396 views

For two planets in a 2:1 mean motion resonance , where will their periastron and apastron points be?

I want to animate the changing orbits of planets when they enter a mean motion resonance. Using a 2:1 resonance, I want to show a low-mass inner planet and a low-mass outer planet being tugged by a ...
1
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0answers
61 views

Is there any free open source planetary orbit simulator software?

I need a free open source planetary orbit simulator software that should be able to calculate orbit stability for a couple simple planetary systems. Basically, I need to calculate orbit durations for ...
1
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0answers
102 views

Reduced Three-body problem

I know that three-body problem in celestial mechanics can't be solved analytically in general. But suppose that the 3rd body is much smaller than the others, so it does not perturb their orbits. This ...
1
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0answers
85 views

How to calculate orbital eccentricity from the ratio of satellites' velocities?

I have a problem with working out how to calculate the orbital eccentricity from the ratio of two satellites' linear velocities. We know that two satellites encircles the Earth in two elliptical ...
1
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0answers
24 views

The equation of the location of L1

On http://en.wikipedia.org/wiki/Lagrangian_point#L1 it says that the location of L1 can be determined as $\frac{M_1}{(R-r)^2}=\frac{M_2}{r^2}+\left(\frac{M_1}{M_1+M_2}R-r\right)\frac{M_1+M_2}{R^3}$, ...
0
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0answers
27 views

Minimal set of invariants to specify a Kepler orbit

In the Kepler problem, we know that there are various invariants, including: Energy Angular momentum vector Runge-Lenz vector All together these consist of 7 parameters. On the other hand, the ...
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0answers
23 views

References on the 3 body problem

Does anyone know good references for the general 3 body problem? I'm looking for both analytical and numerical approaches.
0
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0answers
30 views

Question about changing the orbits of Kuiper Belt Objects (KBOs)

So, lets say, hypothetically, for space travel or terraforming, we want to move a good sized mostly ice Kuiper Belt Object into a stable planetary orbit around the earth or mars. Looking at the ...
0
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0answers
28 views

Does a classical explanation for planetary perihelion precession exist?

I know that the advancing perihelion of Mercury is explained by GR. I was wondering if a classical explanation is also possible without any ad-hoc physical hypotheses.
0
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0answers
83 views

Algorithm for calculating lunar crescent visibility

Is there a simple algorithm for predicting lunar crescent visibility. Simple enough to do with a calculator at least. Those offered in Meeus' Astronomical Algorithms are a bit too involving to do by ...
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0answers
20 views

Is it possible to calculate Lagrangian isolines for local stars?

Is it possible to calculate Lagrangian isolines for local stars? SciFi descriptions of 'hyperspace' always talk about travel routes between the stars following some sort of route. As a thought ...
0
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0answers
40 views

Restricted three body problem

I have the restricted three body problem, which corresponds, to the equation $ \ddot a-2\dot b -a= \displaystyle\frac{\partial U}{\partial a} $ $ \ddot b +2 \dot a-b = \displaystyle\frac{\partial ...
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0answers
54 views

How can I describe an equation for multiple objects over time?

Lets say i have $n$ different objects that effects each other only by the classic gravity force. I have their initial locations, masses and velocity's: $$ x_1(0),\cdots,x_n(0) $$ $$ m_1,\cdots,m_n ...
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0answers
99 views

Effect of small variable transverse force on satellite orbital precession

Consider a small satellite which moves in a 2D elliptical orbit around a much larger body (e.g. the Sun) under the influence of Newtonian gravitational acceleration $$Ar = G.M/d^2 $$ Next imagine ...
0
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0answers
115 views

Relation between the period of rotation and the period of revolution of a satellite

I read somewhere that the tidal forces between the earth and the moon causes the equality between the 2 periods of the moon and that every planet-satellite system will evolve to this condition (like ...
0
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0answers
91 views

References for circular restricted 3 body problem?

Does anyone know of any good references for the CR3BP -- the circular restricted 3 body problem? Emphasizing on real-life applications, and interpretation of the numerical solutions? Thank you. There ...