Here, Chilean contractors carefully pour an ALMA telescope docking pad.
Each 115-ton ALMA telescope sits on one of these pads. Each pad's foundation is rooted almost 6 feet (2 m) into the ground and is wired with fiber optics and power cables that run back to the AOS Technical Building.
The ALMA array can be rearranged by moving telescopes around to different pads. By rearranging the locations of the ALMA telescopes, the array changes the way it sees the sky. These "configurations" offer the wide range of ALMA's abilities, for example, seeing a planet going around another sun or mapping enormous jets coming out of a galaxy far, far away. So, although 66 telescopes may be here on site, it takes 192 pads to offer enough configurations for the giant, multitalented array.