I have always been fascinated with orreries, those mechanical models of the Solar System (and sometimes beyond). My first personal experience with one was the Grand Orrery housed at Harvard's Museum of the History of Science. I had slipped off during a lull in my step-brother's graduation activities years ago. This beauty was built by Joseph Pope with castings by Paul Revere:


Click the image to see the Museum's description.


Click the image to see the Museum's description.


Pope, a Boston clockmaker, started work in 1776 and finished in 1787. Here's a view of its gearwork with the covers removed. The planets visible include Mars, Venus, Saturn, and the Earth and Moon (the Sun and Mercury have been removed, and Pope had already been building it for years when Neptune was discovered, so he left it out entirely):


Click the image to see the Museum's description.

But you no longer need to be wealthy enough to buy one of these priceless objects nor do you need to talented enough to spend 12 years building one. Here's a screenshot of a really cool and useful orrery that's accessible to everyone online, free!


Click the image to go to the the online orrery application.

Okay, it's not gorgeous brass and wood driven by a hand-crank, but it's far more accurate and accessible. Enjoy!

Best,
Chris