There is a tiny chance of earth colliding with Mars or Venus. The only redeeming factor is that this would happen only after a billion years. This is what the astronmers have calculated. 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.