# Thread: Planets throwing comets off course

1. What is the equation or set of equations to tell if a planet will throw a comet off its original course on a fly-by?

2.

3. You don't need an equation, since there is no if. When there is a flyby the comet's course will always be changed.

4. well is there something to figure out what the new course would be? and when the planet changes the comets course, could it pull it into the roche limit even if it doesnt pull it directly toward the planet?...or can you find the new course from kepler's laws?

5. Originally Posted by Darth Lord Sidious
well is there something to figure out what the new course would be? and when the planet changes the comets course, could it pull it into the roche limit even if it doesnt pull it directly toward the planet?...or can you find the new course from kepler's laws?
There's a lot of good information here:

http://www.nature1st.net/bogan/orbit.../gravasst.html

7. Originally Posted by Darth Lord Sidious
What is the equation or set of equations to tell if a planet will throw a comet off its original course on a fly-by?

8. i know that one, thats the gravitational attraction between two objects. i guess what im looking for is say there is an asteroid or comet on a straight path, is there an equation or something that dictates if the planet will capture the asteroid, throw it off its original course, or just enough gravity to slow its speed? or what amount of gravitational attraction from that equation will capture the asteroid? i know the Gravitational Sphere of Influence, but cant find where the different boundaries lie that the planet will capture the object, throw it off its original course, or just slow its speed? ...im really bad at explaining things LOL.

9. Originally Posted by Darth Lord Sidious
i know that one, thats the gravitational attraction between two objects. i guess what im looking for is say there is an asteroid or comet on a straight path, is there an equation or something that dictates if the planet will capture the asteroid, throw it off its original course, or just enough gravity to slow its speed? or what amount of gravitational attraction from that equation will capture the asteroid? i know the Gravitational Sphere of Influence, but cant find where the different boundaries lie that the planet will capture the object, throw it off its original course, or just slow its speed? ...im really bad at explaining things LOL.
It is not that simple.

You need to read a book on the subject of orbital mechanics.

Orbital Mechanics by Conway and Prussing is a good one.

10. ok, will do, thanks. and its funny u said that cuz literally i just found this booklet from NASA about orbital mechanics from the library at the college i go to

11. "Space Flight: Application of Orbital Mechanics" if anyone wants to take a gander. its old but informative.