Spider Crater: Australia's Ancient Asteroid Scar — and What It Reveals About Earth's Violent Past

A remote stretch of the Western Australian outback holds something that looks, from space, exactly like an enormous spider.

Eight jagged ridges radiate out from a central dome. No roads. No towns. No biological explanation. Just ancient rock, silence, and the frozen scar of a collision that happened before complex life existed on Earth.

NASA published the image this week. The structure is called Spider Crater. It looks exactly like its name. And it is just one of hundreds of Earth wounds most people have never heard of.

What is Spider Crater?

Spider Crater is a confirmed impact structure in the remote Kimberley region of Western Australia. It stretches roughly 11 kilometres across — big enough to swallow central London. The distinctive "legs" are not actually legs. They are radial drainage channels: ancient rivers that carved themselves outward along fracture lines in the rock after the impact, over millions of years, following paths of least resistance away from the central dome.

That dome — the spider's "body" — is a geological feature called a central uplift. When a large impactor strikes rock at high speed, the ground beneath briefly behaves like a liquid. It rebounds upward in a massive pulse. Then it freezes in place. What you see at Spider Crater is that frozen rebound, preserved for close to a billion years.

Why does it still look so perfect?

Most of Earth's impact craters look nothing like craters. Vegetation buries them. Erosion grinds them flat. Oceans drown them. Tectonic plates pull them apart or drag them under the mantle. A crater that formed in a tropical jungle vanishes within a few million years. One that formed on an ocean floor gets subducted and simply ceases to exist.

Australia is different. The outback sits on some of the oldest, most geologically stable rock on the planet — the Pilbara and Kimberley cratons, billions of years old, barely disturbed since the Proterozoic era. No active mountain-building. No glaciers. Just flat, ancient, bone-dry desert. And time.

That is why Spider Crater still looks like a spider. Everything else got erased. This one survived.

How many times has Earth actually been hit?

Here is where it gets unsettling. 190 confirmed craters sounds like a lot. It is not. Not when you compare Earth to the Moon.

The Moon's surface shows roughly 300,000 impact structures larger than one kilometre across. The Moon is smaller than Earth. It has been exposed to the exact same stream of space debris for the same 4.5 billion years.

Earth was hit at least as often. We just cannot see it anymore.

Tectonic activity subducted the evidence. Oceans swallowed it. Ice erased it. The genuine number of significant impacts Earth has absorbed in its lifetime is likely in the hundreds of thousands. We have confirmed 190. The rest have vanished — or are still hiding under ice sheets, ocean floors, and kilometres of sediment no one has drilled through yet.

What hit Spider Crater?

The impactor was probably a few hundred metres across. Call it a rock roughly the size of a city block — somewhere between 200 and 400 metres — arriving at a velocity of 10 to 70 km/s.

For comparison: a rifle bullet travels at about 1 km/s. This was ten to seventy times faster.

The energy released on impact was equivalent to hundreds of nuclear weapons detonating simultaneously. The rock beneath did not just fracture. It liquefied. Melted material sprayed outward in a ring. The central dome formed in seconds — a geological structure that would take volcanoes millions of years to build, produced in the time it takes to snap your fingers.

Australia's other hidden scars

Spider Crater is not alone. More than 30 confirmed impact structures have been identified across Australia — one of the highest concentrations on Earth.

Wolfe Creek Crater in Western Australia is nearly perfectly preserved: a bowl almost 900 metres across and 60 metres deep, so alien in appearance it was used as a filming location for an outback horror film. Gosses Bluff in the Northern Territory is a 22-kilometre ring visible from orbit, formed roughly 142 million years ago. Aboriginal Australians know it as Tnorala — a cosmic cradle that fell from the Milky Way. The oral tradition and the geological science converge in ways that are worth sitting with.

Scientists estimate there are likely dozens more buried under Australia's sedimentary basins, detectable only through gravitational anomalies and deep drilling. The famous Chicxulub impact structure — the one that ended the non-avian dinosaurs — was hidden under the Gulf of Mexico for decades before anyone suspected it was there. Australia almost certainly holds surprises of comparable scale.

Is Earth still being hit today?

Yes. Constantly. The scale just varies enormously.

Smaller debris burns in the atmosphere every day — those are the meteors you see on clear nights. Objects large enough to survive to the surface arrive several times a year, almost always over ocean or uninhabited land. Objects capable of making a crater like Spider Crater's — a few hundred metres across — arrive somewhere on Earth roughly every few thousand to tens of thousands of years. The exact frequency is uncertain, and different crater-counting models give different answers, but no serious researcher disputes the basic timeline.

Objects capable of ending civilisation arrive on timescales of hundreds of thousands to millions of years. On geological timescales, that is not a comfort. It is a matter of when, not if.

You can watch the 15,968 tracked objects in Earth's orbital neighbourhood — the same catalog that feeds planetary defense systems worldwide — on the SkyLens live tracker. Understanding the mechanics of how we track these objects starts with understanding why craters like Spider exist at all.

Why does Spider Crater matter now?

Spider Crater is not a warning. It happened 900 million years ago, before animals had complex organs, before fish had jaws, before the first forests.

But that is exactly what makes it significant. The scar is still there. Preserved in remote outback rock, visible from orbit, photographed by a NASA satellite, published on the internet, and now in front of you.

The universe's violence runs on timescales that dwarf human civilisation. Spider Crater is a reminder of that scale. Earth has absorbed hundreds of thousands of similar strikes. We have found 190. The rest are either gone — or still hidden, waiting for someone to look in the right place.

One of them may be the size of Chicxulub. We just have not drilled there yet.

Read more about the forces shaping our planet and solar system in our space stories archive.