Solar system wobble could smash Earth into Mars.

From Daily Mail:

A wobble in the precise clockwork of the solar system could see the Earth collide with Mercury, Mars or Venus, scientists predict.

But they say reassuringly that such a mishap is unlikely to occur for billions of years.

The orbits of the planets are not completely stable because of the gravitational interplay between them.

Over time, the system can become increasingly disordered - like a poorly balanced tyre that eventually tears itself off the axle of a moving car.