The Planetarium was a long chamber located at the base of the Tower of First Knowledge of the Jedi Temple on Coruscant. Situated next to the Tower's main entrance on the first level, it contained large bronzium replicas of several planetary bodies.
Erected in the Tower of First Knowledge circa 1000 BBY, the Temple Planetarium was unique due to its use of physical representations as opposed to those strictly made of holograms. In use for nearly a millennium, the Planetarium was slightly expanded when a large statue of the slain Jedi Master Qui-Gon Jinn was erected in a small rotunda off the main chamber.
After the three years of fighting that made up the Clone Wars, the Temple was invaded and routed by Darth Vader and the 501st Legion of the Grand Army of the Republic. The Planetarium was badly damaged and left in ruins, a testament to the might of the resurgent Sith Lords.
Nearly two decades after the Jedi Order was exterminated, the Galactic Empire maintained a small force at the Temple's entrances. Stationed within the Planetarium were several stormtroopers and Purge troopers capable of dealing with any Jedi who might attempt to enter the complex. In search of clues to his heritage, the former Sith assassin Starkiller entered the Temple's Planetarium and began to decimate the troopers there. While the room sustained even more damage, Starkiller's visit was brief and the room returned to its dormant state.
Untouched throughout most of the Galactic Civil War, the Planetarium would eventually be destroyed when the five spires of the Temple collapsed during the catastrophe with the Lusankya and were cleared away.  While the Temple was rebuilt by the order of the Galactic Alliance, it is unknown if the Planetarium was restored in the structure; though the old blueprints were followed extremely closely with only minor changes.
Located on the first floor of the Tower of First Knowledge, the Planetarium was situated off of the Spire's main entrance. Accessed via a hall that leading from the left side of the Spire Entrance the room wrapped around nearly a quarter of the central shaft that made up the heart of the tower. A long windowed hall, the center of the room was dedicated to the massive repulsorpad and holoprojector that created the planetary display. Several smaller bronzium globe orbited a larger central one with small holo-planets and other satellites buzzing around.
Along the inner wall of the main space were balconies which displayed statues and artifacts of the Jedi Order; expansive bas-reliefs were hung under the balcony's banister. Heritage tapestry hung from the vaulted ceiling, and large tablets declared the Jedi Code. Sunken areas near the windowed exterior wall were littered with podiums upon which busts of some of the Order's greatest minds rested, along with vases and urns collected from across the galaxy. Meditation benches were stacked neatly in areas for use by Jedi wishing to focus on the energies in the chamber.
At the end of the hall was a raised rotunda filled with stained-glass windows; a towering statue of Master Qui-Gon Jinn was erected in the center of the room. Immediately before the rotunda was an low, wide-mouthed access portal which led to a narrow hall that winded around the central shaft, ending in a balcony overlooking the open space.