Giant shadows

The sun is low in the clear blue sky above the Chajnantor Plateau, and the giant dishes of the Atacama Large Millimeter/submillimeter Array (ALMA) cast long shadows across their desert surroundings. The dishes are all either 7 or 12 metres in diameter, and weigh over 100 tonnes. ALMA is the most powerful astronomical observatory of its kind, observing millimetre and submillimetre wavelengths to study the building blocks of stars, planetary systems, galaxies and life itself.