why does predicting things in space (outside the planet) seem to be a lot easier than predicting weather on Earth?

Question

why does predicting things in space (outside the planet) seem to be a lot easier than predicting weather on Earth?

In: Physics

Answer 1

Space is easy; it’s empty. The overwhelming majority of interactions in space are just gravity pulling things around.

Weather is the sum total of the 10^44 molecules in Earth’s atmosphere all bumping into each other. That gets hard to calculate with precision beyond short-term predictions.

So compare a system with 10^44 objects interacting vs. a system with 11 objects interacting (i.e. the Sun, the planets, and whatever individual object you care about).