Dome

Detail, nighttime color-coded hours in rings for the hour, city and time zone (Berlin Fernsehturm in the background); A world clock is a clock which displays the time for various cities around the world; this clock displays 148 cities on one ring of the metal cylinder. The cylinder has 3 rings; an hour ring rotates between the 24 world time zones shown. On top is a simplified representation of the solar system with planets (spheres) and their paths shown with steel circles, which rotates once a minute. The 16-ton clock was installed in 1969 when the Alexanderplatz re-design was almost complete (Erich John was part of the design team). The metal sculptor Hans-Joachim Kunsch helped construct it. Since July 2015, the Urania World Clock is a German listed building. Source: Wikipedia; http://en.wikipedia.org/wiki/Main_Page (accessed 8/5/2015)