As well as the largest planetarium in Hesse, the Orangery palace also houses the Cabinet of Astronomy and Physics, the Landgravial collection of scientific intruments.
The place takes visitors on a journey through Landgravial Kassel's technological and scientific past, providing insights into the departments of Astronomy, Experimental Physics, and Mathematics/Information Technology, as well as the newly created »Measuring Time and Space« thematic complex.
For teaching and research purposes the Landgraves collected, among other things, vacuum pumps, microscopes, electrizing machines, clocks featuring seconds pendula, and early calculating machines. Through their clockwork-driven simulations of the movement of celestial bodies, mechanical celestial globes and artist-created astronomical clocks helped observers to understand the world. From Landgrave Wilhelm IV in the 16th century, the collecting passion and the interest in the natural sciences, and astronomy in particular, was passed on through the generations, and the collection kept growing.