The Moon Globe is the world’s largest and most detailed topographic model of the Moon. 3.5 meters in diameter and 39 sqm in surface, it is exactly 1 million times smaller than its cosmic original: one millimeter of the model corresponds to one kilometer of the Moon.
In 2009, the NASA sent its LRO orbiter to the Moon. Equipped with a laser surveying instrument, it captured the Moon’s topography with an accuracy of 10 centimeters. Two high-resolution cameras photographed the Moon with a resolution of up to 50 centimeters per pixel. In the beginning of the Moon Globe’s manufacturing process, only part of the Moon’s topography was captured by laser scanners – however, high-resolution photographs of the complete lunar surface were already available. In close collaboration with the astrophysicist Prof. Hanns Ruder and the German Institute for Aerospace Technology, the available laser scan data and the photographs were merged with photogrammetric procedures. The result was the most precise and detailed topographic data set of the entire lunar surface to date.
During the manufacturing process, the globe was divided into equal pentagons and hexagons, similar to the surface of a football. The individual segments were milled in Polyurethane foam on a 5-axis CNC milling machine with a precision of 3 millimeters. The process took about nine months, after which the milled forms were coated with carbon fibers, making the globe especially sturdy while extremely lightweight. The resulting 32 segments were assembled, prime coated, and painted after photographs. Through this exact and thorough procedure, the joints between the segments are completely invisible from a viewing distance of 2 meters.
Today, two Moon Globes are on display – one in the Astronomy Exhibition, another one in the Lunar Science Center. A motor makes the model rotate about its own axis. The lighting installed simulates sunlight to make its relief appear the most realistic possible. An interactive projection has been additionally installed in the Lunar Center, enabling visitors to mark individual lunar craters and track them during the rotation of the globe.
The Earth Globe on display in the Astronomy Exhibition shows the Earth’s topography with a never before achieved precision. The Globe has a diameter of 3.5 meters and, like the Moon Globe, is made of carbon fiber material. Likewise, the Earth Globe has been divided into pentagons and hexagons to achieve a total of 32 segments. In the manufacturing process, the surface of the segments was milled into 0,3 Millimeter cuts. Overall, a milling track of over 130 kilometers was created. For the relief to be visible for exhibition visitors, its elevations had to be heightened by the factor six. For some flatland areas, an even higher elevation was necessary. A motor specifically built for the Earth Globe makes the model rotate uniformly about its own axis which is tilted by 23.5°.