Philadelphia's Franklin Institute is hosting the traveling exhibition Galileo, the Medici and the Age of Astronomy until September 7. To celebrate, Smithsonian Magazine put together a slide show of Galileo's gear, er "Instruments of Discovery." This is an Armillary Sphere. From Smithsonian:
At the center of this instrument sits a globe representing the earth. The bands around it pivot on a common center and illustrate the paths of the sun and moon, known planets and important stars. The device was invented sometime in the last few centuries before Christ, but the sphere became widely used in Europe by a thousand years ago. This armillary sphere dates to 1578."Galileo's Instruments of Discovery"