🚀 go-pugleaf

In article <BzuuwB.9Cq@news.udel.edu> bjacobs@chopin.udel.edu (William J Jacobs) writes:
>>Now, could an asteriod which is perturbed out to the orbit of Neptune, be
>>captured by that planet? If so, what would cause the energy loss that would
>>be needed to put it into orbit? I doubt if atmospheric braking would do
>>the trick.
>>
>>Bill
>>
>There aren't many other options.  To lose energy, you need to knock into
>something.  You have the choice of lots of little things (the atmosphere) or
>one big thing  (Neptune itself).  But I'm really no expert on orbital mechanics,
>so I'll some physics jock give more details (should be plenty of folks who 
>know here in sci.space).
>
Maybe if the planet has a more massive moon that the asteroid can shed
energy to, thus allowing it to slow down enough to get captured?  The 
preexisting moon would get to orbit further out, using that newly acquired
energy?  I don't mean a collision, but just gravitational interactions.