Silhouette against a golden sky

One of the giant dishes of the Atacama Large Millimeter/submillimeter Array (ALMA) is silhouetted against a vivid orange sky as the sun sets in this striking footage from the Chajnantor Plateau. ALMA comprises 66 such dishes, each one either 12 or 7 metres in diameter. Together, they form the most powerful astronomical observatory of its kind, helping astronomers to study the building blocks of stars, galaxies, planetary systems and life itself. To minimise noise generated by the thermal emission of the receivers themselves, the dishes are cooled to a temperature of -269 degrees Celsius, just a few degrees above absolute zero.