Four ALMA antennas on the Chajnantor plateau

Time-lapse of a whole night at the ALMA Array Operations Site (AOS), located at 5000 metres altitude on the Chajnantor plateau, in the II Region of Chile, where three of the first ALMA antennas are being tested as part of the ongoing Commissioning and Science Verification process. Because they are pointing at the same target in the sky at any moment, their movements are perfectly synchronised. As the sky appears to rotate clockwise around the south celestial pole (behind the rightmost antenna), the centre of the Milky Way, initially visible in the upper left as a yellowish bulge crossed by dark dust lanes, disappears from view. At the same time, a barely visible Large Magellanic Cloud (LMC) hides behind the rightmost antenna. Then, just before the Moon sets and the sky and the landscape turn visibly darker, the Small Magellanic Cloud (SMC) rises, from behind the dish of the most distant antenna in the image. The SMC is followed again by the LMC, which shows up between thin high clouds during the second half of the night. The Magellanic Clouds are irregular neighbouring galaxies of the Milky Way. ALMA, the Atacama Large Millimeter/submillimeter Array, is the largest astronomical project in existence and is a global partnership between the scientific communities of East Asia, Europe and North America with Chile. ESO is the European partner in ALMA.

This sequence is available in 1080p and stereoscopic 3D from José 
Francisco Salgado (josefrancisco.org).