Climbing the Driest Place

Polly came in from the Pacific coast at Antofagasta and crossed into the Atacama Desert.

There is no good description of the Atacama for someone who has not been there. It is the driest non-polar desert on Earth. Some weather stations in its core have never recorded a single drop of rain. The desert is, by some definitions, one hundred and fifty million years old. Older than the Andes themselves. Older than flowering plants.

The air above it is so dry, so still, and so free of light pollution that more than half of the world's professional ground-based astronomy happens within four hundred kilometres of here.

Polly climbed. The ground below her was the colour of cinnamon and rust. Salt flats appeared in the distance, blinding white. Volcanoes rose in the haze of the Andes to the east.

Her destination was Cerro Paranal, a mountain about two thousand six hundred metres above sea level, capped by four enormous white domes. The European Southern Observatory had built the Very Large Telescope here in 1998. The four domes house the four primary mirrors of the VLT, each eight point two metres across.

Polly followed a minibus up the access road to the residencia, the underground hotel where staff sleep. The residencia was buried in the side of the mountain. Only a small swimming pool with a glass roof was visible from the air. Astronomers were not allowed outside during the day. The desert is hostile to skin. The pool was the way to be near water for one hour a day.

A man in a long-sleeved sun shirt was climbing out of the pool. He saw Polly. "Are you with the cosmochemistry group?" he asked in Spanish-accented English. Polly tilted her head. He smiled and walked into the residencia.

The sun was high. Polly's shadow on the white concrete was sharp enough to cut. The air was thin.

She perched in the shade. From here, the four white domes of the VLT were visible on the summit above, closed against the day. They would open one by one after sunset.

She waited for night.