Visitors from outer space
Australia has been slammed by thousands of celestial rocks over the ages, but thanks to our turbulent and erosive atmosphere, much of the evidence has been rubbed away.
A closer look at the moon shows how many impact scars remain on an airless, waterless world.
Yet there are still a handful of sites in remote parts of Oz where speeding space boulders have left their mark.
We take a look at four locations that got in the way of cosmic debris.
1. Wolfe Creek (Kandimalal) Crater
In geological terms, the 14,000-tonne Wolfe Creek meteor is a relatively recent arrival, hurtling through the atmosphere about 120,000 years before Mick Taylor’s emphatic anti-backpacking message.
Estimated to be travelling at a head-spinning 17km per second, the meteorite punched a 900m-wide hole into the Western Australian outback.
Wolfe Creek’s remote location makes it particularly dramatic; the 55m-deep crater rises 25m above the spinifex-speckled plains on the edge of the Great Sandy Desert.
It’s a steep, 400m-return clamber up the crater’s rocky flank for views of the vegetation rings inside, which are thought to be associated with a seasonal lake that forms in the centre.
Getting there
It’s about 946km from Alice Springs to Wolfe Creek Meteorite Crater National Park, via the sealed Stuart Highway and the largely unsealed Tanami Road, which can be all sorts of rough.
To avoid this remote outback crossing, travellers will need to take the alternate – much longer – route via Katherine, Kununurra and Halls Creek. So, you might want to add a few other attractions to your itinerary like the Kimberley region and the rest of WA.
Entry is free and there’s bush camping on-site.
2. Lake Acraman
About 580 million years ago, a giant asteroid ploughed into the desert on the edge of the Gawler Ranges in outback South Australia. The impact site has undergone considerable erosion and its circular-ish shape is only obvious from the air.
Some researchers suggest the original crater may have been up to 90km in diameter, but others claim it was around 35-40km wide, slightly larger than the salt lake it created.
The mighty planetoid hit with such force that debris spread to a region we now know as the Flinders Ranges, some 300km to the east. At the time there were no mountains, just a vast inland sea.
Material dislodged from the asteroid’s impact, settled into the water above earlier deposits, and over the millions of years that followed, other layers of sediment piled on top.
Much later, towering mountains formed that were considerably higher than the Flinders we see today.
When erosion chewed into the ranges, a thick, greenish band was exposed in the rock face, which is still visible in Brachina Gorge – this is the asteroid layer.
Getting there
Lake Acraman is on the privately-owned Moonaree pastoral lease, but it can be viewed from Hiltaba Nature Reserve, which is open from 1 April to 31 October.
Hiltaba is about 752km north-west of Adelaide, via the sealed Eyre Highway to Wirrulla and 68km of unsealed road towards the end of your journey.
The reserve is accessible in a conventional vehicle with decent clearance, but a high-clearance four-wheel-drive is needed to tackle some of the property’s tracks.
Accommodation and camping are available.
3. Tnorala (Gosse Bluff)
Scientists believe a 600m-wide comet rammed this hefty dent into Central Australia 143 million years ago. A 4.5km-wide circle of towering bluffs is all that remains of a crater that was originally 20km across.
It’s an other-worldly thrill driving into the crater through a gap in its walled structure. Surrounded by the eroded remnants of this landscape-smashing event, it’s hard to comprehend the mayhem that occurred here so long ago.
Although Tnorala is sacred to the Western Aranda people, respectful travellers are welcome to visit the site and enjoy the marked walking trails to scenic vantage points.
Getting there
Tnorala Conservation Reserve is 187km west of Alice Springs via the sealed Larapinta Drive and Namatjira Drive. A four-wheel-drive is recommended for the last 6km.
Facilities include a picnic shelter and toilet, but camping isn’t permitted.
Apply online for a Parks Pass.
For a dramatic view overlooking Tnorala and the surrounding terrain, head for Tylers Pass lookout, which is 15km north of the Tnorala access track turnoff, on the sealed Namatjira Drive/Red Centre Way.
4. Henbury Meteorites
Racing towards its demise at 40,000km/h, the Henbury meteor broke into fragments before impact, creating 12 small craters in the central Australian desert (main photo).
The 4700-year-old craters range in size from a shallow, 6m-wide dent to a more substantial, 180m-wide, 15m-deep hole. The area can be explored on a short walking trail.
Pieces of the mostly iron space rock can be viewed at the Museum of Central Australia.
Getting there
Henbury Meteorites Conservation Reserve is 145km south-west of Alice Springs.
Follow the sealed Stuart Highway south for 130km, before turning right onto the unsealed Ernest Giles Road. After 10km, turn right again onto the reserve access road.
The unsealed sections can be rough at times, but it’s usually suitable for sturdy, high-clearance conventional vehicles if conditions are dry.
Entry and camping fees apply and sites can be booked online.