"There's only one way down," our guide says with a nod towards the steep, 100-metre sand dune that stretches from our vantage point at the top of the ravine into the valley below. With some trepidation, I edge on to the top of the dune, taking in my extraordinary surroundings: jagged, red ridges rippling into the distant slopes of the Andes. I take a few steps and am soon hurtling down the dune, a spray of rust-coloured sand at my heels.
Death Valley seems an apt name for a place where the only sign of life appears to be the handful of sandboarders zig-zagging the slopes below us. We are in the heart of northern Chile's Atacama Desert, a vast plateau sandwiched for 1,000km between the Pacific Ocean and the Andes. Its positioning in a rain shadow, combined with high atmospheric pressure and the cool winds from the Pacific, make it one of the driest places on earth.
The magnificence of the scenery and the thrill of dune-running leaves our small group giddy with excitement. We press on to the Valley of the Moon to catch the sunset over its lunar landforms. The top of the valley offers a widescreen view of the Andes, which turn from orange to crimson to dusky pink in a stunning nightly display under reliably cloud-free skies.
There's a sense of otherworldliness in the Atacama Desert, so it's fitting that it has become one of the most important sites on the planet for exploring what lies beyond our atmosphere. It is here, in this inhospitable landscape, that the world's largest astronomical project is based. Inaugurated in 2013, Alma (Atacama Large Millimeter/submillimeter Array) is a global collaboration to study the cool universe – the matter between the stars. From here, scientists are able to observe the birth of stars and planets near our solar system and detect distant galaxies forming at the edge of the observable universe.
Next month Alma will be opening its doors to the public for the first time. Visitors will be able to take a tour of the Operations Support Facility (OSF) which will include a short talk, video of Alma's history and a view of any antennae that are under maintenance. However, Alma's 66 operational antennae won't be accessible; while the OSF sits at 2,900 metres above sea level, the antennae are spread out on a plateau at an altitude of 5,000 metres over distances of up to 16km.
Alma director Pierre Cox explains that the tours are being launched in response to increasing demand. "The public is very interested in how the observatory works and what it looks like, so the organised visits will offer them the opportunity to interact with it," he says.
Atacama's dry, cloud-free skies, high altitude and lack of light pollution haven't gone unnoticed by amateur astronomers either; travellers with an interest in the night sky have been coming here for years. I'm based in the small town of San Pedro de Atacama, the main hub for travellers exploring the eastern edge of the desert. It's also home to Space Obs, which has been giving visitors an introduction to the night sky through its popular Star Tour for the past decade. I'm eager to see what it has in store.
I dress in as many layers as possible (the temperature plummets to around freezing at night) and waddle to the meeting point in town. A 15-minute drive delivers our group of 20 to the Space Obs camp, with the lights of the town far behind us. We pour out of the bus and cluster together in the darkness around our guide, a Canadian called Les. There is excited chatter as we look up at the incredible canopy of stars, the clear arc of the Milky Way startlingly defined.
Les talks us through the wonders of the southern night sky and how to locate some of its most famous constellations. Shining brightly is Alpha Centauri which, despite being the closest star system to our sun, would still take more than four years to travel to at the speed of light. Then there's Orion Nebula, a star nursery, easy to find once you've located Orion's Belt. Les shoots a green laser to pinpoint each subject, star names and mind-boggling statistics coming thick and fast.
After an hour we shuffle through the darkness towards 10 telescopes which are each trained on different celestial objects. Through them, what appears to the naked eye as a single star is revealed as a cluster of thousands, while Saturn, which was indistinguishable from the other stars, emerges in all its ringed glory.
On the drive back to town I can't peel my eyes from the window, my mind buzzing with all the new information. Atacama's landscape might be otherworldly, but it's nothing compared to the celestial displays above it.
Hotel Poblado Kimal (00 56 55 2851030; poblado.kimal.cl). Doubles from $190 (£125).
Space Obs Star Tours (00 56 55 2566 278; spaceobs.com). Tours cost 20,000CLP (£20.80). Alma tours are due to start next month (almaobservatory.org)