With a group of astronomers, I went to Llano de Chajnantor, 5100m above sea level in the Atacama, to see the ALMA observatory being constructed. We drove from San Pedro to the ALMA base camp, near the village of Toconao at 2900m above sea level. We had medical tests here, to check blood pressure and oxygenation, before heading on up to the heights. I knew from previous trips to high altitude that I was probably going to feel spaced out and confused, and it turned out as I expected; I felt a little bit out of body by the time we got up to 5100m, hardly able to understand what people said to me and only capable of shuffling slowly across the plateau from the main building to the antennae.
My oxygen-deprived memories are very hazy but I think it was probably awesome. The array is not complete and only about a third of the eventual number of antennae have been installed so far, but it looked incredibly futuristic with all of the dishes strung out across the barren desert plateau. I staggered around and took lots of photos, and occasionally took shots of oxygen from the canisters we'd all been given.
On the altiplano, snow melts in strange ways. It forms peaks and valleys, and the valleys deepen until you're left with large snow pillars called penitentes standing in the red desert landscape.
I went to Laguna Chaxa, where flamingos paddled in the shallow waters. The scenery was breathtaking, with the salt plains, lakes, volcanoes and deep blue sky all looking otherworldly. I'd crossed the Salar de Uyuni six years ago, and it was flat, white and it tasted of salt. The Salar de Atacama was different - rumpled and dirty grey and apparently containing all sorts of things like arsenic and lithium. I didn't try tasting it.
To my mind, the bus journey between Calama and San Pedro is one of the most spectacular there is. This time I had the seat at the front of the bus, and I spent the whole hour and a half just staring out and enjoying the views of the driest place on Earth.