Janus and Epimetheus

I used to be scared that the universe was a genuinely random place. Scared there was no destiny, no design, no wheels within wheels.

Fuck that.

In the last 10 years or so I’ve come to not only accept randomness but embrace it. Which is part of my fascination with orbital mechanics (the overarching theme of this blog), the complex structures and counter-intuitive oddities created by the accumulation of countless collisions and near misses. By chucks of rock hitting the sweet spot of a gravity well at just the right angle and speed.

For instance, there's these guys:

This is a picture of Janus and Epimetheus, two moons orbiting Saturn just outside the F ring. Their orbits are very close, about 30 miles apart. And every 4 years or so, when they line up just right, they switch orbits, narrowly avoiding a collision in the process. 4 more years, they switch back. The orbits are actually pretty stable.

As much as anything is stable out there.

More on that later.