Four ALMA antennas on the Chajnantor plain

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. As the Moon sets at the beginning of the night, three of the first ALMA antennas start tests 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, stationary 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. Then, the Small and Large Magellanic Clouds, two neighbouring galaxies of the Milky Way, rise from behind the two antennas on the right. The flashes on the ground are the car lights of the guards patrolling at the AOS. ALMA, the Atacama Large Millimeter/submillimeter Array is the largest astronomical project in existence and is a truly 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 (


ESO/José Francisco Salgado (

About the Video

Release date:18 August 2010, 14:33
Duration:54 s
Frame rate:30 fps

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