There are ten major deserts here, and they cluster into two great families. In the west, a near-continuous arid expanse joins the Great Sandy, Little Sandy, Tanami, Gibson and Great Victoria, the largest of them all. In the east, a smaller group gathers the Simpson, Sturt, Strzelecki and Tirari, with the little Pedirka stranded on its own between the two clusters. They are not uniform sheets of sand. The country shifts between red dune seas, stony gibber plains scattered with wind-polished rock, salt pans, sandstone mesas, open tree savannah and the dry beds of rivers that flow perhaps once in a generation. The Simpson, with its ranks of longitudinal dunes, is among the most striking, and Lake Eyre, which fills completely only about once every 25 years, sits at the low heart of the eastern basin.

The land beneath all this sand is staggeringly old. Its geology spans more than 3.8 billion years, and the great cratons that underpin it, the Yilgarn, the Pilbara and the Gawler, hold some of the oldest rocks on the planet. The dunes themselves are young by comparison, sculpted by wind into long ridges that march for hundreds of kilometres in near-perfect parallel. By international standards these deserts are not the driest on Earth; many places see around 250 millimetres of rain a year. But the sun is fierce and the ground gives water back to the sky almost as fast as it falls, so the land lives in a permanent thirst. Frost is rare in the north, though winter nights can turn sharply cold, and the heat of high summer is relentless.

It is tempting to call this country empty. It is not, and it never was. Aboriginal peoples have lived in these deserts for at least 50,000 years, occupying every region including the driest, and many remain the recognised traditional owners of vast tracts of the interior today. The Arrernte, Luritja and Pitjantjatjara are among the desert peoples; the Dieri country spans the Simpson, Strzelecki and Tirari. They moved through clearly understood tribal lands, lived on the bush foods of the country, and guarded their waterholes with a care that meant survival. The rock art runs deep in time, with some images in the Pilbara and South Australia estimated at around 40,000 years old. As recently as 1984, the Pintupi Nine walked out of the Gibson Desert having lived a fully nomadic life until that moment. Today about a third of Australia's deserts are Aboriginal land, much of it managed as living homeland and as one of the artistic heartlands of the nation, from the watercolours of Albert Namatjira onward.

European exploration came late and at a price. Charles Sturt pushed into the Strzelecki and Sturt Stony deserts in the 1840s chasing a fabled inland sea that did not exist. Ernest Giles named the Gibson Desert in 1874 for Alfred Gibson, who vanished in it and never came out. Peter Egerton Warburton struggled across the Great Sandy and reached the coast half-blind, alive only because of his Aboriginal tracker, Charley. The Simpson was the last great barrier, named in 1929 by Cecil Madigan after the industrialist Alfred Simpson, and not crossed by a European until 1936, when Ted Colson made it over the dunes with the Aboriginal man Peter Ains and a string of camels. Those camels, brought in from the 1850s and handled by cameleers from Afghanistan and beyond, were what finally made the interior passable. Some still roam wild today; Australia now holds the largest population of feral camels on Earth.

For all its severity, the desert teems in its own restrained way. Australia's arid zone holds more species of lizard than anywhere else on the planet, more than forty in a single area, alongside thorny devils, perenties up to two metres long, and woma pythons. After rare heavy rain the land transforms: salt lakes brim, dormant frogs surface, and wildflowers run across the dunes. Spinifex grass clumps anchor the sand, mulga scrub shades the plains, and river red gums trace the lines of watercourses that are dry far more often than not. Tourism now draws hundreds of thousands of visitors a year to Uluru, Kata Tjuta and the dune crossings, while mining digs deep for iron, gold, opal and uranium. Through it all the Royal Flying Doctor Service, flying since 1928, stitches the scattered communities together, a reminder that out here distance itself is the defining fact of life.