Is the solar system stable?

In an introductory post, I wrote about Henri Poincaré’s attempts to model the behaviour of three bodies orbiting each other. He found that the mathematics of this problem showed that the behaviour of such a system was complex and could become unstable.

As the solar system is made up of a lot more than three bodies (one sun, eight planets, several moons, and many smaller bodies), the obvious question arising from Poincaré’s work is to ask whether the solar system is stable. Indeed, this question seems to have been one of the drivers of Poincaré’s work.

Ian Stewart has written a fascinating article which attempts to answer this question. The short answer is ‘probably not’. Luckily, the timescales involved are unlikely to worry us.

The article doesn’t require any prior knowledge of astronomy but it does use a few specialist terms such as Hohmann transfer orbits, Trojan points and Lagrange points.