The first observation of the #JovianMoons was on #ThisDayInHistory in 1610. #GalileoGalilei used his custom telescope and first saw the larger #Ganymede & #Callisto, with the smaller #Io & #Europa sighted the following night. These observations proved the #Copernican solar model.

Custom laser cut and engraved Copernican orrery is one of my favorite pieces in my collection. Gear ratio plans were purchased and enclosure designed and created back in 2020.

www.lisaboyer.com/Claytonsite/...

#orrery #copernican