"All the microwaves coming down from space would have been absorbed by clouds or water vapour in the atmosphere before they reached our instruments. That is why we picked Chajnantor," says astronomer Dr. Murdin.
Chajnantor is high and dry - perfect for picking up microwaves. This selection is also particularly appropriate, for mankind has been exploiting the aridity of the Atacama desert for millennia.
But collecting microwave radiation has one major drawback, as Esteban Illanes of the European Southern Observatory, explains. 'It is absorbed by water. An observatory at sea level would pick up nothing.
Chajnantor's receivers will be built specifically to collect this precious microwave radiation and help astronomers understand one of science's last major cosmological mysteries: the structured, solid nature of the cosmos.
However, really distant, and therefore older, galaxies recede from us so rapidly that much of their light is transformed - by an effect known as the Doppler shift - into microwave radiation.
It sounds extraordinary. Nevertheless, the European Southern Observatory has committed itself to begin building an array of giant microwave receivers on Chajnantor.
These aren’t your typical loos. One uses microwave energy to transform human waste into electricity. Another captures urine and uses it for flushing. And still another turns excrement into charcoal.