The Effelsberg 100-m radio telescope of the Max-Planck-Institut für Radioastronomie (MPIfR) is located in a creek valley directly crossed by the border line between the states of Northrhine-Westfalia and Rhineland-Palatinate in Germany. It can be reached from a parking lot close to the two villages Lethert and Effelsberg, both parts of the town of Bad Münstereifel. From there it’s a walk of about 15 minutes to the visitors’ pavilion in sight distance to the telescope. Along the connecting road a topical astronomy trail has been assembled, the “Planetary Trail”, scaled 1 : 7.7 billion (1 : 7.7 x 109), covering the distance of 766 meters from the parking lot (panel “Pluto”) to the visitors’ pavilion (panel “Sun”). The Planetary Trail was built in 2004 and leads from dwarf planet Pluto and the outer gas giants in the solar system along the inner rocky planets including the Earth to the sun which is displayed as a concrete ball of about 40 cm diameter in the courtyard of the pavilion.
Planet trail and radio telescope route, Effelsberg GE