Questions tagged [orbital-mechanics]

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

Filter by
Sorted by
Tagged with
2
votes
1answer
130 views

On orbital mechanics of evaporating planets

A planet orbits around its sun on an elliptic orbit, and loses mass slowly due to evaporation. How will the parameters of the orbital ellipse change as a function of time? Could we do a generalisation ...
-2
votes
1answer
225 views

Calculate eccentricity with altitude and semiminor axes

Following on from this question, I wish to know how to find the reverse - how to find eccentricity given a Semi-minor axis & altitude. I want to use something based on $$b=a\sqrt{1−e^2}$$ but ...
0
votes
1answer
55 views

Intercept a NEO trajectory

I need help with an exercise in the book that I can't tackle. I need to calculate how much time we have to intercept and eliminate a NEO. I got the following orbital parameters: a=-2791.44 km (semi-...
7
votes
1answer
574 views

Effects of the solar tide on planets

It’s well known that (lunar) tides on Earth result in a transfer of angular momentum from Earth proper to the Earth–Moon orbital motion. That’s why the Moon resides now in a high Earth orbit, and ...
12
votes
5answers
26k views

Is the Sun in our solar system moving or stationary?

When I was small, I read that Sun is fixed at the center of the solar system and that all the other planets rotate around it. But later I heard that even the Sun is not fixed; it moves. Is this true? ...
3
votes
1answer
269 views

Binary stars of different ages?

In an answer on a different SE someone raised the point that “common” explainations published never discuss stars being captured. Presumably binaries are formed as pairs, or team up while still in ...
11
votes
3answers
806 views

How do I know, mathematically rather than from observation, if a moon is full?

I know about the equations to describe the orbit of a moon around a planet. I know the moon's semi-major axis and eccentricity, and the same for its host world with the star they orbit. Is there any ...
2
votes
1answer
288 views

What is the most asymmetric known planet?

Planets are more or less spherical, can you tell which one is the most asymmetric? Do they figure out such a property from an eccentric behaviour, or what? I have a simple technical question: an ...
2
votes
1answer
262 views

Is the radius used in the formula for the escape velocity the average radius of the celestial object or the radius at the starting location?

I learnt that the escape velocity is given by $$v_e = \sqrt{\frac{2GM}{r}}$$ Say I want to launch a rocket from the earth into space and want to calculate the escape velocity $v_e$ (I guess without ...
4
votes
1answer
254 views

Will Gaia detect inactive neutron stars?

Will the astrometric precision of the Gaia space telescope be able to detect the gravitational influence of cold old solitary neutron stars on the movements of stars? At least in a statistical sense ...
3
votes
3answers
1k views

Inverse of the sunrise equation - finding locations with a given sunrise time on a given day

I'm working on a project for fun where I represent some sleep data geographically. For a given day, I have a date, a time for falling asleep that night, and a time for waking up the next day. The idea ...
0
votes
1answer
1k views

The Three Elements in the Milankovitch Cycles

According to the Serbian geophysicist Milutin Milankovitch, there are three elements that make an ice age possible: Eccentricity (orbital shape): Varying between 0.000055 and 0.0679 over the course ...
8
votes
1answer
481 views

What is the shape (along the plane, not up-down) of stellar orbits in flat spiral galaxies

What I mean is, with a central mass orbits are relatively simple, but orbits around the galaxy are different, in essence as the star orbits through the dark matter halo, the further it moves away from ...
1
vote
1answer
159 views

Distance and orbital period for terrestrial binary planets

This article, http://phys.org/news/2014-12-binary-terrestrial-planets.html, suggests binary planets could orbit each other at a distance of only three planet radii. For two earth-like planets, that is ...
3
votes
1answer
186 views

Have any co-orbital exoplanet pairs been discovered (and not subsequently retracted)?

For this question, I think a good working definition of co-orbital configuration would be two bodies orbiting around a third much larger body in a 1:1 resonance and where neither mass is negligible. ...

1 2 3 4 5
6