“You didn’t mention camping on Mars.”
My wife had a point: thin air, thinner soil, extreme UV, rocks straight from a Nasa red-planet image, jagged ranges – all ideal backdrops for a movie set. No wonder the place was considered for training by the Apollo program. Its sparse life forms include an intimidating shrub whose thorns mimic the stingers on the scorpions that come out after dark. A harsh, forbidding place, but beautiful too. We made shade with our camper awning and waited for magic time: the desert at dusk.
Travelling along the Stuart Highway it’s easy to miss the Henbury Meteorites conservation reserve, 12km off the tarmac along a rough track one and a half hours south of Alice Springs. We’d seen samples of its space rock in the excellent display at the Museum of Central Australia in Alice and were keen to see where they fell. There are six known impact sites in the territory and the two most accessible are Henbury and Tnorala (Gosse Bluff). We visited both during Victoria’s fifth Covid lockdown in 2021.
Henbury is a site where a nickel-iron meteor about the size of a garden shed disintegrated before striking the land to carve out over a dozen impact craters, just 4,500 years ago – so recently that the site has significant cultural meaning as a sorry place for the Luritja people, whose sacred songs and oral histories tell of this devastating event.
Scientific models suggest the meteorites hit Earth at 40,000km/h in an explosion akin to the Hiroshima blast.
The site’s 12 craters are best viewed when the sunlight’s low angle reveals the smaller, heavily eroded examples. Among the youngest of Earth’s known impact sites, Henbury’s pits have been scoured by wind and rare deluges down the Finke River flood plain. Extreme temperatures do the rest.
The largest crater is 180m across, the smallest the size of a back-yard spa. The explosion sprayed out tonnes of pulverised rock in a distinctive rayed pattern still visible around Crater No 3 – the only known terrestrial example. Temptingly, specimens of the actual meteorite hurled out may still be found. The 45kg chunk in the Museum of Central Australia is one example of 680kg collected so far, though digging or damaging the site without a permit is illegal. We don’t find any meteorite fragments but we leave with memories of a humming sunrise and night with a billion almost touchable stars.
From Tylers Pass lookout, two hours west along the Namatjira Drive from Alice Springs, Tnorala (Gosse Bluff) appears as a mountain range thrusting incongruously from the endless western plains. In fact, these peaks were created in seconds when an object up to 1km wide hit the Earth at about 250,000km/h, 142m years ago, with an explosive force at least 20 times more powerful than all the world’s nuclear weapons.
No trace of that object has been found, so it was probably an icy comet that vaporised on impact. Erosion has since reduced the crater from its original 22km diameter. Satellite images uncannily resemble a staring eye under a sunburnt brow.
Specimens in the Museum of Central Australia show that early Cretaceous central Australia was wetter and cooler than it is now, with abundant dinosaurs. Locally, they would have been vaporised, and anything living within 100km killed by the massive shock wave and extreme heat.
The sound of the explosion probably travelled around the world. The Tnorala bolide event was a prelude to the big one, Chicxulub on Mexico’s Yucatán peninsula, which wiped out the dinosaurs 77m years later.
In their oral traditions, Western Arrernte people understand Tnorala as a cosmic impact site. A group of star woman were dancing in a corroboree in the Milky Way when one woman placed her baby in a turna (wooden cradle). The dancing shook the galaxy and the turna slipped, with the baby falling to Earth as a blazing star, striking the ground to create the crater’s distinctive bowl shape.
These days “awesome” is a word debased by glib use. It’s apt driving into the 5km-wide Tnorala crater, surrounded by cliffs 180 metres high, formed in a blink by a literally Earth-shattering event as our planet’s crust rebounded to form the crater’s inner ring. The rock strata in these peaks show that some were lifted from a depth of 4km by incredible explosive force and are now inverted.
It’s not just awareness of this ancient violence that marks Tnorala as a sorry place. Local information boards describe it as a pre-colonial massacre site. So it’s doubly proper that camping is forbidden.
It’s an unwelcoming place, where an object large enough to be classified as a city-killer fell from the sky. This kind of comet is now thankfully detectable by telescopes such as the new Vera C Rubin observatory in Chile, and also proven as feasible they could be steered off course.
So forget Mars. Cancel that ticket. Instead, visit awesome central Australia – where the mountains are upside down, the stars greet your fingertips and the dawns are so silent you can hear the sun sing.
Need to know
The Museum of Central Australia is hosting a Henbury Meteorite reserve discovery day on 10 August as part of National Science week.
Henbury: Day trips to the Henbury Meteorites conservation reserve require a Northern Territory parks pass and the site can be reached by 2WD vehicles, however 4WDs are recommended. The reserve’s basic facilities include picnic shelters and a drop toilet. Water and firewood are not available. Campsites must be booked online through Northern Territory Parks and fees apply. The nearest food and fuel supplies are available 85km south at the Erldunda Roadhouse on the Stuart Highway.
Tnorala (Gosse Bluff): The Tnorala crater is accessible via a sandy track and offers picnic shelters and a drop toilet. Camping is not permitted in the reserve due to its status as a registered sacred site of the Western Arrernte people. Fuel and food is available at Hermannsburg, 62km east on the Namatjira Way. Travel beyond Tnorala is by 4WD only and requires a Mereenie Tour pass. Many of these roads may be impassable in wet weather.
• Associate Prof Duane Hamacher assisted with factchecking for this story
