There’s some astonishing stuff going on in the Andes, high up where we humans have trouble breathing.
The ALMA (Atacama Large Millimeter/submillimeter Array) astronomical observatory is being located on the 5000m plateau of Chajnantor, in the Chilean Andes. That’s high. It’s very high. At that height only half as much oxygen is available as at sea level, so it’s very difficult to work there.
100 tons here, 100 tons there
It’s an interesting observatory. Rather than having one single telescope on one spot, this observatory consists of 200 pads, spread over distances of up to 18.5 km.
The pads are docking stations with connections for power and fibre optics.
66 antennas are placed on the pads to operate as a single, giant telescope. Each antenna weighs about 100 tons and has a diameter of 12 metres.
Depending on exactly what observations are required, the antennas are moved from pad to pad to create the required configuration.
They’re moved on giant transporters, guided by a laser steering system and fitted with ultrasonic collision detectors. The transporter positions each antenna with an accuracy of a few millimetres.
The ALMA antennas are the most advanced submillimetre-wavelength antennas ever made. They are designed to operate fully exposed in the harsh conditions of the Array Operations Site. This means surviving strong winds and temperatures between +20 and -20 Celsius whilst being able to point precisely enough that they could pick out a golf ball at a distance of 15 km, and to keep their smooth reflecting surfaces accurate to better than 25 micrometres (less than the typical thickness of a human hair). …
The telescope will observe the Universe using light with millimetre and submillimetre wavelengths, between infrared light and radio waves in the electromagnetic spectrum. Light at these wavelengths comes from some of the coldest, but also from some of the most distant objects in the cosmos. These include cold clouds of gas and dust where new stars are being born and remote galaxies towards the edge of the observable universe.
The high plateau
It’s a curious feeling to be up at 4,000 metres where life does not naturally exist. There were no plants, birds, nor any signs of anything living, apart from humans.
As sunset came around we were up at the top, by the many telescopes. We couldn’t actually visit any, of course, as they’re busy with expensive and serious research, but we walked around the outside of a couple as they opened up. Then we watched the sun set.
Fortunately the tour company had provided us with extremely warm Arctic jackets and gloves.
Life at 4Km was odd. I bet at 5Km it’s even odder.
I think I may be adding a tour to Chajnantor to my life’s wishlist.