Earth Could Collide With Other Planets

Everybody put on your helmet; Smivs writes "Astronomers calculate there is a tiny chance that Mars or Venus could collide with Earth — though it would not happen for at least a billion years. The finding comes from simulations to show how orbits of planets might evolve billions of years into the future. But the calculated chances of such events occurring are tiny. Writing in the journal Nature, a team led by Jacques Laskar shows there is also a chance Mercury could strike Venus and merge into a larger planet. Professor Laskar of the Paris Observatory and his colleagues also report that Mars might experience a close encounter with Jupiter — whose massive gravity could hurl the Red Planet out of our Solar System."

Comments

Re:I'm no physicist ...

[Lord Dreamshaper]

Think of it in terms of two cars colliding head-on, literally on a planetary scale: the planetary crust that seems like solid rock to you on the human scale is more like the crumple zone of a car's frame. When the planets collide, they would buckle and fuse together. In the example of 2 cars colliding, there would likely be some rebound and the cars would come to rest a few feet apart (the cars' respective centres of gravity are insignificant compared to the forces of friction on the pavement). On the planetary scale, what's left of the planets' respective centres of gravity would continue to pull & keep them together (with a relatively small percentage of debris lost, most of that would then be recaptured into orbit for the immediate future).