Looking at that map, it's wild how many "confirmed impact structures more than 100km wide" there are <i>just in Australia</i>. There must be dozens of mass extinction events that we don't know about because the fossil record is so unclear past 500Mya.<p>[0]: <a href="https://en.wikipedia.org/wiki/Extinction_event" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Extinction_event</a><p>[1]: <a href="https://en.wikipedia.org/wiki/Chicxulub_crater" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Chicxulub_crater</a><p>[2]: <a href="https://en.wikipedia.org/wiki/Earth#Natural_history" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Earth#Natural_history</a>
Wow that's a huge crater. It's bigger than the Vredefort impact structure in South Africa. The Vredefort dome is the second oldest at 2 billion years old that can be seen here:<p><a href="https://upload.wikimedia.org/wikipedia/commons/b/b5/Vredefort_Crater%2C_South_Africa%2C_OLI_satellite_image%2C_27_June_2018_cropped.png" rel="nofollow noreferrer">https://upload.wikimedia.org/wikipedia/commons/b/b5/Vredefor...</a><p>And the full-sized version:<p><a href="https://upload.wikimedia.org/wikipedia/commons/5/52/Vredefort_Crater%2C_South_Africa%2C_OLI_satellite_image%2C_27_June_2018.jpg" rel="nofollow noreferrer">https://upload.wikimedia.org/wikipedia/commons/5/52/Vredefor...</a><p><a href="https://en.wikipedia.org/wiki/Vredefort_impact_structure" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Vredefort_impact_structure</a>
I know it's buried deep, but it's kind of weird for the reporting to not even show an image of the area? Perhaps a map with a little pin indicating where the Deniliquin structure is?<p>They say it's near the city of Deniliquin, which is here [0]. Oddly, that spot doesn't even show on the map of yellow dots of likely impact structures! Did they forget to mark their newly discovered largest-impact-crater-in-the-world on the map?<p>[0] <a href="https://goo.gl/maps/shvRY2CiEs3eR8iw5" rel="nofollow noreferrer">https://goo.gl/maps/shvRY2CiEs3eR8iw5</a>
I have always thought Lake Michigan/Huron look mighty round if you follow from the north end down through Green Bay and the Fox river to the west, and cut into Canada along the Niagara Escarpment [1] on the East. There seem to be signs of a round structure all the way down in Ohio. But while this does form a roundish structure, the history is quite different than an impact:<p>[1] <a href="https://en.wikipedia.org/wiki/Niagara_Escarpment" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Niagara_Escarpment</a><p>Still I wonder, what if this other stuff happened in this shape because of a giant impact crater billions of years ago before all that?
Article says the center of the impact crater is (was?) around 30km deep. Curious how big they think the asteroid that caused this was. The article doesn't mention anything, and a lazy search online came up with nothing.<p>Wondering just how big of an asteriod this was, and how capable we are of seeing candidate asteroids of this size.
Lets say the same asteroid hit the same place in Australia today....<p>How many people would both directly from impact/shockwave and indirectly die (infrastructure collapse, tsunamis on beach towns, climate change, etc) from this, do we think?
This kinda discovery is why I hold out hope there were super advanced ancient civilizations on earth. They just happened to figure out Stargates and peaced out entire cities to safer off-world locations.
Should we as a species be more concerned about a mass extinction event like this? The longer we survive, the more likely it'll happen. Isn't it just a matter of time?
<i>I think it may have triggered what’s called the Hirnantian glaciation stage, which lasted between 445.2 and 443.8 million years ago...<p>This huge glaciation and mass extinction event eliminated about 85% of the planet’s species.<p>It was more than double the scale of the Chicxulub impact that killed off the dinosaurs.</i>