Illustration by Detlev van Ravenswaay, Science Source
Published February 14, 2013
There's one physical connection that isn't going down after Valentine's Day this year: Earth and asteroid.
The asteroid known as 2012 DA14 will narrowly miss Earth this Friday, the closest asteroid flyby on record. But the planet has not always been so lucky.
Earth's craters are enduring testaments to direct asteroid hits. And though millions—in some cases billions—of years of erosion have made it difficult to determine the exact size of the meteorites, there is a general scientific consensus around the world's largest craters, which mark the largest asteroid impacts.
Here are the ten biggest known:
1. Vredefort Crater
Asteroid impact date: Estimated 2 billion years ago
Location: Free State, South Africa
Specs: Also known as the Vredefort Dome, the Vredefort crater has an estimated radius of 118 miles (190 kilometers), making it the world's largest known impact structure. This crater was declared a UNESCO World Heritage Site in 2005.
2. Sudbury Basin
Asteroid impact date: Estimated 1.8 billion years ago
Location: Ontario, Canada
Specs: The Sudbury Basin is considered one of largest impact structures on Earth, with an estimated diameter of 81 miles (130 kilometers). Dating back 1.8 billion years, it is also one of the oldest known impact structures in the world.
3. Acraman Crater
Asteroid impact date: Estimated 580 million years ago
Location: South Australia, Australia
Specs: Located in what is now Lake Acraman, this impact structure has an estimated diameter of 56 miles (90 kilometers).
4. Woodleigh Crater
Asteroid impact date: Estimated 364 million years ago
Location: Western Australia, Australia
Specs: This crater is not exposed at the surface and has led to many discrepancies regarding its actual size. Reports on its diameter vary from 25 to 75 miles (40 to 120 kilometers).
5. Manicouagan Crater
Asteroid impact date: Estimated 215 million years ago
Location: Quebec, Canada
Specs: This impact crater formed what is now Lake Manicouagan. Even with erosion, it's considered one of the largest and best-preserved craters on Earth, with an estimated diameter of 62 miles (100 kilometers).
6. Morokweng Crater
Asteroid impact date: Estimated 145 million years ago
Location: North West, South Africa
Specs: Located near the Kalahari Desert in South Africa, this crater contained the fossilized remains of the meteorite that created it.
7. Kara Crater
Asteroid impact date: Estimated 70.3 million years ago
Location: Nenetsia, Russia
Specs: Now greatly eroded, the Kara crater is a non-exposed impact structure in Russia. Some have claimed that the impact structure actually consists of two adjacent craters: the Kara and the Ust-Kara crater.
8. Chicxulub Crater
Asteroid impact date: Estimated 65 million years ago
Location: Yucatán, Mexico
Specs: Located on the Yucatán Peninsula in Mexico, many scientists believe that the meteorite that left this crater caused or contributed to the extinction of the dinosaurs. Estimates of its actual diameter range from 106 to a whooping 186 miles (170 to 300 kilometers), which if proved right could mean it's the biggest.
9. Popigai Crater
Asteroid impact date: Estimated 35.7 million years ago
Location: Siberia, Russia
Specs: Russian scientists claim that this crater site contains trillions of carats of diamonds, making it one of the largest diamond deposits in the world. These diamonds have been referred to as "impact diamonds."
10. Chesapeake Bay Crater
Asteroid impact date: Estimated 35 million years ago
Location: Virginia, United States
Specs: Discovered in the early 1980s, the Chesapeake Bay Crater is located approximately 125 miles (201 kilometers) from Washington, D.C. Some estimates suggest this crater is 53 miles (85 kilometers) wide.
I Believe I've stumble across "I Believe" a super massive crater in the south east area of the United States with Birmingham Alabama being at it's center peak and the crater rim radius span across counties stretching from Georgia to Mississippi. The crater rim consist of counties from Corinth Mississippi Temple Mississippi Columbus Mississippi Selma Alabama Montgomery Alabama Columbus Georgia Macon Georgia and Athens Georgia with the impact direction coming from the northeast through the Appalachian of Kingsport Tennessee Knoxville Tennessee Chattanooga Tennessee Gadsden Alabama to Birmingham Alabama.
P.S. Birmingham Alabama is known for large deposits of iron ore.
I think you're right! And the ridge and valley region of the Appalachians is sloughed-off supracrustal-rock strewn field from the aqueously-differentiated surface of the trans-Neptunian object, the same as Belcher Islands in Nastapoka arc impact (circa 12,800 ya) and a bunch of the sloughed off supracrustal rock from the Nastapoka impact rafted into the Labrador Trough atop the chunks of the Laurentide ice sheet.
Guy, we've got to get together on this!
I cannot believe that the largest impact ever to hit planet earth located in the XiJian region, has not been recognized as such. There is a huge basin that appears to have been caused by a meteor or comet the came from the east hitting earth at an angle. This area is boardered by Kyrzstan to the north, Nepal to the south, Xijian to the east, Tajikistan to the west and Mongolia to the northeast.
Study that region via Google Earth. That entire area from China almost all the way to the Holy Land, is terribly convulsed and shows obvious signs of extreme heat and molten activitiies for thousands of miles. As one looks at the odd plateau that is the Andes which appears to have stopped the molten flow to the south, one realizes that whatever it was almost melted a mountain range. The molten activity seems to have flowed south below the southeastern edge of the basin the flow extending down into Yunnun. There is also a molten flow pattern going west from the basin to Kabal and south from Kabal.
The bible referrers to the lake of fire and I wonder if the region I am referring to was the actual Lake of Fire. Historians claim that the Dead Sea is the lake of fire because of it's depth and gas bubbles and similar phenominas that have occured on that sea. I believe that those activies may be due the extreme depth and a possible subterranian connection.
Another glaring factor in this theory is the evidence of extreme heat in this huge area.
An interest thought here is connected with ancient folk lore or myth that said that Lucifer became a comet and God threw Lucifer to the earth. There is a lot of discussion about Bible translations and whether they are literal. There is no conclusive answer but there is a lot about this universe that we don't understand.
submitted by Pat Wendt, Soldotna, Alaska
read an interesting theory : http://dinosaursonthetwinplanet.tumblr.com/
I made a map of them here.
There is always more to a story than meets the eye and if it were not for laws passed by the guilty to protect the guilty, the public would know of the perpetrators of injustices before they are six feet under.
Was DA14 real? Probably, but possibly not. People often believe what they read, especially when legitimacy is implied by a position in a societal hierarchy. I would believe a scientist coming back from the field with data, the one who collected it and speaking face-to-face. But these days with so many ways to falsify data, the Internet where nothing is real, heartless and biased corporate interest in science and upper management of scientific organizations being leaned on by partisan international organizations, the truth is becoming more elusive.
Was it a random event that the Russian-Chelyabinsk meteor, biggest in a hundred years (Tunguska 1908) would arrive hours before NASA's 2012 DA14 to thoroughly upstage it? I think not...
My blog post on this upstaging of NASA.
@Chris Thomas Wakefield I think I can put a name and a face to your planet-X, and it may be a vastly bigger deal than anyone realizes. Consider that the relative alignment of extended scattered disc objects, like Sedna and 2012 VP-113, could be due to a former brown-dwarf Companion to the Sun that merged in an asymmetrical binary spiral-in merger, 542 Ma, gaining escape velocity from the Sun, ushering in the Proterozoic Eon and seeding the solar system with brown-dwarf /super-Jupiter lifeforms, known as the Cambrian Explosion.
Hold tight, you've got a tiger by the tail!
I've always considered the Chelyabinsk meteorite to be a shot across the bow. To have a large object passing the earth and a strike in Russia at the same time is unprecedented in modern times..
Taking the long view, I have come to the conclusion the neighborhood just ain't that safe...
I am leading a group of grade 8,9 students under the guidance of the Canadian Planetary Science Center to check out an unusual lake called Red Berry Lake in central Saskatchewan Canada.
We think it might be a potential impact crater because of it's unusual features, surrounded by a ring of hills. We are going looking for "shock rock". We have been given a whole bunch of indicators to look for. It would be very cool if a grade 7 and 8 science class got to be part of finding an impact crater.
Please look up Redberry Lake on Google Maps and see what you think. It is also a much deeper than average lake in our area and it is a salt water body as the ring of hills does not let water flow out of it.
Tell me what you think, and if National Geographic, if you want to help us in early June we would Love your help.
Take a peek at polar bears playing, swimming, and sleeping in their changing habitat.
By winning protection for their boreal forest, indigenous Canadians help slow global warming.
Our correspondent reports from a Norwegian research ship that's drifting inside the Arctic ice cap, gathering data needed to predict its future.
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