Our Solar System built as an experiment in Three.js. The planets are roughly to scale, orbit speed is also roughly scale. Disatances between planets however is scaled down quite significantly (roughly 1/4 the actual distance between planets). The scale distances between the gas giants didn't make for a very engaging experience. Scales are commented out at the top of initialize.js.
Nothing to setup No dependencies
Note: Please use the local copy of Three.js in the repo, it has a line of code changed to stretch images around planetary rings properly.
If you have a Google Cardboard VR, I have integrated this with Cardboard Web App so that you feel as though you are on top of the sun looking down on the Solar System.
http://brockbeldham.github.io/threejs-solar-system-experiment/cardboard