Solar System
Interactive 3D solar simulation with planet tracking, orbital mechanics and real-time comets.
About this one
Coursework, and it shows in the best way: this came out of a Coursera course I was taking on interactive 3D, where the brief was a solar system and the interesting part was everything the brief did not cover — tracking a planet while it moves, keeping the orbital mechanics readable at wildly different scales, and putting comets on screen without the whole thing turning into a screensaver.