Giant Impact Crater Found In Australia

An anonymous reader writes "One of the largest meteorite impacts in the world has been discovered in the South Australian outback by geothermal researchers. It may explain one of the many extinction events in the past 600 million years, and may contain rare and exotic minerals. The crater is said to have been 'produced by an asteroid six to 12 km across' — which is really big!"

Comments

Re:discovered?

[LingNoi]

Obviously not in the article.. not even one damn picture of it..

But how much energy is that?

[Zaphodox]

Okay so they give widely varying estimates of the crater's size - assuming the centre value of 120 Km a +/- 60 Km ia one hell of a margin of error. I imagine that the energy released from such an impact is orders of magnitude greater than any nuke we could ever throw at each other. The article metions the release of CO2, but i thought that by definition asteroids were just lumps of rock. So where does the CO2 come from after the impact?

Re:But how much energy is that?

[Trogre]

I would guess the ground. When a meteor hits land, a lot of the ejected material is from the ground, not the meteor itself. Rocks apparently have a lot of oxygen and carbon locked up in them.

Re:discovered?

[captainpanic]

Obviously not in the article.. not even one damn picture of it..

It is very difficult to photograph something that is 80-160 km across and buried under many layers of sediments... that may have something to do with the lack of pictures.
TFA doesn't mention when the discovery was made, so it is hard to say how much time they've had to produce some images for the media.

I can imagine that specialized satellites can scan the area for geological differences. But I imagine that Google Maps shows no sign of this crater at all.

Where?

[DeathToBill]

TFA doesn't mention a location. There is a roughly circular sort of feature in about the right place and about the right size centred here:

http://maps.google.com.au/?ie=UTF8&ll=-28.614665,141.139984&spn=0.806518,1.234589&t=h&z=10

You can see it better if you zoom out a couple of steps. It's not very well defined, and may just be wishful thinking on my part!

Re:Where?

[atomicstrawberry]

You're looking for a roughly circular feature? I think this is a more likely spot personally:

http://maps.google.com.au/maps?sll=-28.87835,141.047974&sspn=4.39095,8.453979&ll=-35.310258,149.125156&spn=0.015987,0.033023&t=h&z=16

Obligatory

[antifoidulus]

"You call that a meteorite? THIS is a meteorite!"

Re:discovered?

[Anonymous Coward]

> they could have at least shown a map of the region with a yellow circle to indicate where they think it is.

They said the geothermal researcher who discovered this crater was working in the Cooper Basin, South Australia.

http://en.wikipedia.org/wiki/Cooper_Basin

This is where it is:

http://www.hydrocarbons-technology.com/projects/CooperbasinAust/images/2-cooper-basin.jpg

The geothermal energy project in that area of the world is near the town of Innaminka.

http://en.wikipedia.org/wiki/Innamincka,_South_Australia
http://en.wikipedia.org/wiki/File:Innamincka_location_map_in_South_Australia.PNG

The geothermal energy project is there because the earth's crust at that location is unusually thin.

http://www.smh.com.au/news/environment/hot-rock-power-the-way-ahead/2007/04/11/1175971183212.html
http://www.adelaide.edu.au/adelaidean/issues/9461/news9469.html

The earth's thin crust in that area may actually have something to do with the impact crater.

This is a quite remote part of the world. Desert. There is almost nothing there.

It is not really surprising that this impact crater has not been discovered up until now.

Re:discovered?

[flyingfsck]

That impact crater is dwarfed by some other structures on earth: The Bushveld complex in South Africa is several hundred kilometers across, but it is so old (> 2 billion years = half the age of the earth) that it is not clear how it formed. Either a gigantic volcano, or a gigantic metor impact could have caused it.

Especially limestone

[wiredog]

Limestone is calcium carbonate, which releases tons of CO2 when burned.

Re:What would an impact look like?

[careysub]

On TV you see lots of computer sims but none look realistic to me. Would there be a light covering the sky so bright you couldn't see it or would it traverse the atmosphere so quick it wouldn't have time to heat up and you really would see this huge space rock impact. And what would the explosion look like? WOuld it be a fireball initially or would you simply see billions of tons or rock being launched into orbit?

A very useful source of information is the Asteroid Impact Effects on-line program: http://impact.ese.ic.ac.uk/ImpactEffects/

Taking their upper size estimate (12 km) and average impact parameters (17 km/sec, 45 degree angle of entry) this would light up brilliantly at around 120 km altitude and get brighter all the way down its 10 second transit to the Earth. However you would probably not want to be anywhere you could actually see its entry. At a distance of 1250 km you would just see it light up on entry on the horizon, and thereafter the glow would be indirect until impact. THEN - part of the fireball which appear ~5 times larger and brighter than the Sun would rise above the horizon and irradiate you for about half an hour. This would be quite uncomfortable - a first degree thermal burn would develop after several seconds, but you get roasted for a hundred times longer than that, or until the fine ejecta thrown into space comes down and starts blocking your light after 10 minutes of so. And an hour after the impact a 12 psi blast wave with tornado-speed 335 mph winds would hit. This would likely be fatal.