Since Pluto and Neptune cross paths, is there any chance they could ever bang right into each other?

Answer 1

They only apparently "cross paths" in projection. In fact, Pluto and Neptune have different orbital planes (ecliptic) that intersect without the orbital paths directly crossing.
In fact, the points at which Pluto's orbit crosses the ecliptic are both situated outside Neptune’s orbit and are separated by a distance of 6.4 AU or greater than six times the distance of the Earth from the Sun. Not even close!

http://en.wikipedia.org/wiki/Pluto


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Answer 2

There are two reasons they will never collide in their current orbits:

1. Pluto's orbit is in a different plane than Neptune and the other planets. The two nodes where it does cross the plane of Neptune's orbit, are not directly in Neptune's path. So even though Pluto occasionally is closer to the sun than Neptune, they don't actually "cross paths."

2. Neptune and Pluto are in a perfect orbital resonance of 3:2. This means that Neptune orbits the sun *exactly* 3 times for every 2 orbits of Pluto (so they always cycle back to *exactly* the same relative positions). This isn't just an amazing coincidence ... if they were NOT in this stable resonance, then Pluto would long have been pulled disastrously out of its current orbit and collided with Neptune or some other object (i.e. anything not in a stable orbit or resonance got eliminated pretty early in the life of the solar system). This stable configuration has probably lasted for most of the 5 billion years of the age of the solar system, and will probably continue for billions of years more unless some other large body (like a passing star) pulls Pluto out of orbit.

Of the two reasons, #2 is the most significant. It's the reason that #1 can remain true indefinitely (i.e. if they were not in resonance, then Pluto's off-plane orbit would still have come close enough to Neptune to become unstable). But also, even if #1 were not true, and they both orbited in the same plane, #2 (orbital resonance) would keep them from colliding.

Answer 3

The first answer is probably a good fact to go on. But, over time, our Solar System may change and there is always that possibility of a collision. I would assume we would be talking Millions of years for this to happen, or, maybe a large Asteroid collision make it happen sooner. This all Theoretical Speculation. But, it is a thought that is possible.

Answer 4

They don't really cross paths. And even if they did, it's only at two points. There's no way they could ever chance up to meet like that...

Answer 5

May collide with each other, who knows.