A sign on Chajnantor for ALMA optical fibre cable

A sign on Chajnantor plain 5000 m above sea level in the Chilean Andes indicates the location of an underground fibre optic cable for ALMA (Atacama Large Millimeter/submillimeter Array). ALMA is the largest ground-based astronomy project in existence, and will be comprised of a giant array of 12-m submillimetre quality antennas, with baselines of several kilometres. An additional, compact array of 7-m and 12-m antennas will complement the main array. Construction of ALMA started in 2003 and will be completed in 2012. The ALMA project is an international collaboration between Europe, East Asia and North America in cooperation with the Republic of Chile.