What if pluto and neptune collide

Pluto is a tiny Kuiper Belt Object; a ball of rock and ice measuring only 2, km across. This is a tiny fraction of the diameter of Neptune, which is 49, km across. You could fit 20 Plutos side by side to match the diameter of Neptune. Neptune and Pluto have a very interesting orbital dynamic between them.

Because of this, Pluto can actually get closer to the Sun than Neptune. Alex Wills, Hong Kong China I read somewhere that Pluto and Neptune each orbit the Sun with a peculiar frequency that ensures that they will never collide.

Given that they haven't collided over the past 5 billion years or so this seems reasonable. If, for whatever reason they did collide, I imagine that Neptune, being far larger than Pluto would survive, albeit with a slightly altered orbit while Pluto would be destroyed in the collision.

The effect on Earth would be virtually nil. The Earth might be snookered. Darren, Lancaster The closest point of Pluto's orbit is within that of Neptune's, and so their oribits do "cross". There is no chance of a collision however, because Pluto's orbit is quite tilted with respect to the other planets' orbits and so when Pluto does this crossing, it is actually well below the plane that Neptune orbits in.

A collision would be quite spectacular to watch just think back to the comet crash on Jupiter, that made some quite sizable explosions - Pluto is much bigger than a comet , although the system is so far away it will have no effect on the earth.

Over time it will indeed collide. This is a surprisingly successful model and matches the clues we observe better than any of its rivals. If Pluto formed that way, why does it now move on such an eccentric and inclined orbit? And so we have a clue, in the form of the eccentricities and inclinations of Pluto and the other Plutinos. But what does it portend?

As our models of planet formation have become more sophisticated, the simple picture that our planets formed on their current orbits has been overturned. Neptune, in particular, was a great wanderer, with some models suggesting it formed between one and two billion kilometres closer to the sun than we currently observe it.

But how can we tell? As the planets formed, with Neptune much closer to the sun than it is today, there was a wealth of debris planetesimals further out. As Neptune fed, devouring the material closest to it, it scattered material inward from this trans-Neptunian region and, in the process, began to drift outwards.

As Neptune moved, so did the location of its resonances. Objects were captured as the planet swept outwards, forced to move in lockstep with the giant. As it travelled further, Neptune ensnared more objects. Once caught, few escaped, and the rest were carried inexorably outwards, swept ahead of the giant planet. As they were pushed, the force driving them acted to excite their orbits, increasing their eccentricities and their inclinations.

This brings us back to Pluto. From its orbit, and its link to Neptune, we can tell that Neptune must have formed closer to the sun and then moved outwards. That also means that Pluto must have formed closer to the sun than its current orbit.