Martin Vézina's jsOrrery is an impressive simulation of the solar system, and it's made out of JavaScript.
We've seen some excellent JavaScript examples in our time, but jsOrrery is a particularly impressive piece of work. Inspired by a trip to Kennedy Space Centre, Martin Vézina decided to have a crack at simulating the entire solar system (or at least the major bits of it).
He'd previously programmed a basic 2D simulator in Flash, but this time around he decided to try it in 3D, using JavaScript and Three.js, and to make it a lot more accurate. "There are other nice Javascript orreries out there," he says, "but what makes jsOrrery stand out is that it is a realistic visualisation instead of being an artistic or schematic one."
The results are well worth a look. Assuming your browser is up to the job - we had problems in an older Firefox but it gets on perfectly well with Chrome - you're presented with the Sun and all the planets in lovely 3D, with plenty of options to add to the fun. You can view the solar system from all manner of locations, you can focus on particular parts of it, such as the Earth and its artificial satellites, or perhaps the moons of Jupiter, and you can set the entire thing in motion.
You can even enter a particular time and date and see how the planets were aligned at that time, and you can also increase the size of the planets so that you're able to see them as more than little dots in comparison to the Sun.