The world’s largest asteroid impact zone has been found, scientists say

A 400 kilometre-wide impact zone from a huge meteorite that broke in two moments before it slammed into the Earth has been found in Central Australia.

The crater from the impact millions of years ago has long disappeared. But a team of geophysicists has found the twin scars of the impacts – the largest impact zone ever found on Earth – hidden deep in the earth’s crust.

www.washingtonpost.com...

a reply to: nighthawk1954

I'm going to go out on a limb here and say that (if there was life at the time) this was an ELE (extinction level event).

Still a bit confused about this though

It’s now a minimum of 200 kilometers, this makes it about the third biggest anywhere in the world.

How is this the third biggest if it was the biggest?

ETA: largest impact zone because it was two large twin asteroids, but not the biggest single crater in the world. . okay nvm

The zone of impacts of the Carolina Bays is much larger, I think. They stretch from the Atlantic coast of North America to central Kansas. They are usually elliptical, and the major axes point to the Great Lakes area, so they appear to be secondary impacts.

a reply to: FamCore

Yeah, the article mentions that as well.

Glikson and others believe the impact was felt across the world, changing life’s course and spewing a blanket of ash into the atmosphere that blanketed out the sun. “It’s likely to be part of a particular cluster that was linked with a mass extinction at that time,” he told the Conversation.

But dating it has been difficult. Glikson thinks it hit at least 300 million years ago, but “it’s a mystery,” he said. “We can’t find an extinction event that matches these collisions.”

The aliens must've used a giant vacuum cleaner to suck up all the dust...

originally posted by: FamCore
a reply to: nighthawk1954

I'm going to go out on a limb here and say that (if there was life at the time) this was an ELE (extinction level event).

It's hardly "out on a limb" as the article mentions this twice. But nice to provide the acronym. You saw that movie, too. "We know about Ele!" I see what you did there.

originally posted by: nighthawk1954
The crater from the impact millions of years ago has long disappeared. But a team of geophysicists has found the twin scars of the impacts – the largest impact zone ever found on Earth – hidden deep in the earth’s crust.

It doesn't sound like the largest in the world and not even the largest in Australia, unless they mean the largest confirmed but since he's not even dated the impact it doesn't sound very confirmed. This one sounds larger:

Massive Australian Precambrian/Cambrian Impact Structure also known as MAPCIS

The Massive Australian Precambrian/Cambrian Impact Structure also known as MAPCIS is a proposed impact structure based upon arguments presented by Daniel P. Connelly at Geological Society of America meetings.[1] Its center is located approximately equidistant between Uluru (Ayers Rock) and Mount Conner in Australias' Northern Territory. A hypothetical outermost ring is 2,000 kilometres (1,200 mi) in diameter is claimed to be the result of undefined "far field stresses." The crater itself is smaller at approximately 600 km (370 mi) in diameter. Connelly argues that the age of this hypothetical impact is approximately 545 mya which puts it near the end of the Neoproterozoic Era.[2] If confirmed as an impact crater, it would be the largest on earth.

600km is greater than 400km but I think more research is needed on both impacts.

We look at the moon and can easily see the effects of impacts from asteroids. We can see those scars much easier than we can those of our own planet.

Satellite imagery has helped identify some in the recent past. I live inside the blast zone of one found by satellite images here at the mouth of the Chesapeake bay.
impactcraters.us...

We don't like to think about it but we really are just sitting ducks.

Here's a good listing of known Earth impacts. If it's not up-to-date, it's close to it.

Earth Impact Database

originally posted by: Saint Exupery
Here's a good listing of known Earth impacts. If it's not up-to-date, it's close to it.

Earth Impact Database

It apparently shows confirmed impacts. The Wiki on Australian Impacts has two lists, confirmed and unconfirmed.

The topic of this thread (Warburton Basin Impact) and several other large unconfirmed impacts are listed there which don't appear in the "Earth Impact Database", or at least I didn't see them.

Thanks for that link though, it's interesting.

a reply to: Arbitrageur

Interesting and disconcerting.
I read the doom and gloom threads but it's usually to say calm down or nothing to see here.
But this? Well like I said...we're sitting ducks.
Maybe we should start being nicer to one and other.
I'm going to hug my family today just because...

a reply to: nighthawk1954 and Lazarus Short

This was just posted at The Cosmic Tusk
It looks as though the AA tektire strewnfield and the Carolina bays are related and the impacr was in Michigan.

[url=http://]A TALE OF TWO CRATERS: CORIOLIS-AWARE TRAJECTORY ANALYSIS CORRELATES TWO PLEISTOCENE IMPACT STREWN FIELDS AND GIVES MICHIGAN A THUMB [/cosmictusk.com...]

a link to conference

[url=http://]Link to T10. Great Lakes Shorelines: Geomorphology, Quaternary History, and Modern Processes[/gsa.confex.com...]

Michael Davias, Stamford, CT and Thomas Harris, Lockheed-Martin (Retired), Orbit Operations, Valley Forge, PA

Pleistocene Epoch cosmic impacts have been implicated in the geomorphology of two enigmatic events. Remarkably, in both cases spirited debates remain unsettled after nearly 100 years of extensive research. Consensus opinion holds that the Australasian (AA) tektites are of terrestrial origin despite the failure to locate the putative crater, while a cosmic link to the Carolina bays is considered soundly falsified by the very same lack of a crater. Likely >100 km in diameter, these impacts during geologically recent times should be readily detectable on the Earth’s surface. The improbability that two craters have eluded detection informs a hypothesis that a single impact at ~786 ka generated AA tektites as distal ejecta and Carolina bays as progeny of proximal ejecta. The AA astroblem search is focused on SE Asia despite a strewn field encompassing >30% of the Earth’s surface. This spatial scope implies to us that interhemispheric transits should be considered, as does findings that AA tektites were solidified in a vacuum, then ablated on re-entry at ~10 km sec-1. A Coriolis-aware triangulation network operating on the orientations of 44,000 Carolina bays indicates a focus near 43ºN, 84ºW. Referencing the work of Urey and Lin, we propose that a near-tangential strike to the Earth’s limb generated the 150 x 300 km oval depression that excises Saginaw Bay and opens Michigan’s Thumb. That region was likely buried under deep MIS 19 Laurentide ice at 786 ka. Schultz has shown that oblique impacts into continental ice sheets yield non-traditional astroblems, and multiple glaciations have since reworked this site, making identification more challenging. Hypervelocity gun tests show that oblique impacts produce a vertical plume of ejecta, biased slightly down-range. Ballistic trajectories reflecting such a plume deliver tektites to all AA finds when lofted at ~10 km sec-1 and parameterized with the proposed depression’s location and 222º azimuth. Chemical and isotopic characteristics of AA tektites suggest they were sourced from sandstone and greywacke of Mesozoic age, which is congruent with Michigan Basin strata lost when The Thumb developed. The distribution of proximal ejecta may explain anomalous pulses of regolith in moraines and sediment loading in regional drainage basins recently dated ~800 ka using 10Be/26Al methods.

So the low angle impact kicked the ejecta into a transcontinetal ballistic bath and it rained back down in south easst asia.

fascinating stuff.