What Type Of Asteroid Was The Chicxulub Impactor
Most scientists believe the Chicxulub impactor was a solid mass that broke off from a larger asteroid.
It is thought to have had a carbonaceous Chondrite composition.
Carbonaceous chondrites are asteroids made mostly of carbon and other elements.
They are believed to be similar to the material that makes up comets. However, they do not contain water ice.
What Does An Asteroid Strike On Earth Mean For Us
The knowledge that an asteroid between the size of 10-15 kms can have such an extreme impact on the planet has helped NASA and the entire astronomy community in designing threat levels of the asteroids who are likely to approach us in the future. This also tells us how much time we may have to prepare before another such a giant asteroid comes close to Earth. Currently, the largest potentially hazardous asteroid known to NASA is Asteroid Toutatis, at 5.4 kms width.
Nasa Reveals How Big The Asteroid That Killed Dinosaurs Destroyed Earth Actually Was
It was not the first time an asteroid had hit Earth and it was not the largest asteroid to hit Earth. However, somehow, this was the asteroid that killed dinosaurs and destroyed Earth a long time ago. For decades, scientists had been working to find out how dinosaurs went extinct? Back in the 19th and early 20th century, there were some interesting theories ranging from toxic volcanic gasses to food shortage. However, evidence has shown definitively that it was an asteroid strike that wiped the entire dinosaur species from the planet Earth. What exactly was this evidence, how large was the asteroid that hit Earth and killed dinosaurs? These are still important questions to which we must know the answers in order to understand and prepare against any future threat. Well, thanks to NASA, we do know the answers to how large the asteroid that killed dinosaurs and destroyed the Earth was. Read on to find out more.
Dinosaurs first appeared during the Triassic period, between 243 and 233.23 million years ago, although details around their origin is still a hotly debated topic. Interestingly, based on fossil records, birds are actually feathered dinosaurs who have evolved from theropods and are the only lineage of dinosaurs to survive the asteroid strike-fueled extinction. This extinction event took place around 66 million years ago and is known as the CretaceousPaleogene extinction event.
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Earthquakes Airblast Fireball And Tsunamis
After identifying and characterizing the crater, we built computer models of an impact event. We wanted to see if we could replicate the crater and characterize the asteroid and its impact.
The simulation that best fits the crater shape is for an asteroid 400 meters in diameter hitting an ocean that was 800 meters deep. The consequences of an impact in the ocean at such water depths are dramatic. It would result in an 800-meter thick water column. The asteroid, as well as a substantial volume of sediment, would instantly vaporize, with a large fireball visible hundreds of kilometers away.
Shock waves from the impact would be equivalent to a magnitude 6.5 or 7 earthquake, which would likely trigger underwater landslides around the region. A train of tsunami waves would form.
The air blast from the explosion would be larger than anything heard on Earth in recorded history. The energy released would be approximately a thousand times larger than that from the recent Tonga eruption. It is also possible that the pressure waves in the atmosphere would further amplify the tsunami waves far away from the crater.
The Tsunami That Killed Dinosaurs
Imagine for a moment that you are a dinosaur 66 million years ago. You live in the lush coastal plains near where the modern city of Galveston Texas was built in the future. Your life is filled with looking for food, youre carnivorous so you spend your days and nights scouting for food: mammals, small reptiles, even fish. Youve been living in this neck of the woods for decades and nothing much perturbs you. Youre in charge of your destiny.
Then everything changed. It all happened very fast, you see a bright light in the sky to the east, a searing flash, and next, a boom that is the loudest sound youd ever heard, so loud it deafens you . The ground shakes violently: earthquakes almost never occur in these parts and this is a magnitude 13, likely the largest quake Earth has ever felt! Your giant 50-foot-long frame is thrown to the ground and you lie there stunned. Next, you are hit by searing heat, a giant fireball approaches from the ocean, skirting the water, wave after wave of heat burns your skin and you roar in agony. But then you see it — a giant wave coming also from the same direction — you have seen storms before, even some hurricanes, but nothing like this. Its a wall of water, some 90 meters high coming at you, there is nowhere to go, you begin to run towards the land but its no good. After millions of years of dominance, its all over.
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Car Crash Frozen In Place
How did the researchers manage to pinpoint the season in which the asteroid struck?
Even though they were 3,000 kilometers away from the impact crater,the bones of paddlefish and sturgeons preserved in rock at the Tanis site in the Hell Creek Formation provide a unique record of what was perhaps the most significant event in the history of life on our planet.
The fish, which were up to a meter long, died in a dramatic fashion immediately after the asteroid strike, buried alive by sediment displaced as a massive body of water unleashed by the asteroid strike moved upstream. Think of the ripples of water from a stone thrown into a pond, but on a much larger scale.
Unlike tsunamis, which can take hours to reach land after an earthquake at sea, these moving water bodies, known as a seiche, surged out instantaneously after the massive asteroid crashed into the sea.
The researchers are certain that the fish died within an hour of the asteroid strike, and not as a result of the massive wildfires or the nuclear winter that came in the days and months that followed. Thats because impact spherules small bits of molten rock thrown up from the crater into space where they crystallized into a glass-like material were found lodged in the fishes gills.
These impact spherules, they got ejected into space, and some of them may have even circled the moon and then they rained back down on Earth, During said.
The Discovery Of The Crater Of A 2nd Asteroid
We identified the crater using seismic reflection as part of a wider project to reconstruct the tectonic separation of South America from Africa back in the Cretaceous period. Seismic reflection works in a similar manner to ultrasound data. It sends pressure waves through the ocean and its floor and detects the energy that the features reflect back. This data allows geophysicists and geologists to reconstruct the architecture of the rocks and sediments.
Scrolling through this data at the end of 2020, we came across a highly unusual feature. Among the flat, layered sediments of the Guinea Plateau, west of Africa, was what appeared to be a large crater. It was a little under 10 kilometers wide and several hundred meters deep, buried below several hundred meters of sediment.
Many of its features are consistent with an impact origin. These include the scale of the crater, the ratio of height to width, and the height of the crater rim. The presence of chaotic deposits outside of the crater floor also look like ejecta, material expelled from the crater during a collision.
We did consider other possible processes that could have formed such a crater, such as the collapse of a submarine volcano or a pillar of salt below the seabed. An explosive release of gas from below the surface could also be a cause. But none of these possibilities are consistent with the local geology or the geometry of the crater.
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What Happened During The Impact
Asteroids hit Earth typically at high speeds of 16 to 32 km/sec . During the impact, the kinetic energy in the asteroid is converted to explosive energy, blowing debris of dust, soil, and rocks not only into the atmosphere, but out into space, where it fell back into the top of the atmosphere. Early calculations in the 1980s showed that so much dust entered the high atmosphere that the Earth was shrouded in a dust layer that blocked sunlight for several weeks or months. This would have killed some plants, disrupting the food chain.
Later calculations indicated that for the first few hours after the impact, rocky debris would have fallen back into the high atmosphere, creating a storm of glowing fireballs in the sky. The radiant energy from these would have heated the surface to boiling temperatures for some minutes, and would have been enough to kill many animals and plants on the surface. However, in regions of heavy rainstorms or snowstorms, these organisms would have survived the first few hours. Sea creatures would have been buffered from effects in the first hours, but plankton on the surface might have died out over the weeks of darkness, decreasing the food supply for small fish, which affected the bigger fish, and so on.
Life In Different Hemispheres
The new study of the Tanis fish is not the only research of its kind: In December 2021 a separate team led by DePalma published their own analysis of the season captured at Tanis in the journal Scientific Reports. The two papers rely on different fossils and use different techniques, yet they reach broadly similar conclusions. DePalmas results suggest that Chicxulub hit in the spring or summer, consistent with Durings more constrained finding of a springtime impact.
We applaud independent research work and analyses, and are pleased that these projects complement each other to lead to a richer understanding of the prehistoric world, DePalma, a professor at Florida Atlantic University and a Ph.D. candidate at the University of Manchester, said in an emailed statement.
The new studys authors hope that the data will feed into further analyses of how the extinction event at the end of the Cretaceous period played out. For instance, tentative signs from a few Southern Hemisphere sites suggest that after Chicxulub, the Southern Hemisphere recovered about twice as fast as the Northern Hemisphere did. How much could this signal be affected by the season of the impact?
More clues could be waiting in the Southern Hemispheres fossil record, which has been studied less thoroughly than the Northern Hemispheres. I think that there’s a real treasure trove there , if we can get more funding toward the countries that are lacking the data, During says. That’s a massive gap.
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Were All Breaks In The Evolutionary Record Caused By Asteroid Impacts
Probably not. The biggest known break is the break between the Paleozoic Eara and the Mesozoic Era, about 230 to 250 My ago, when something like 90% of then-existing species died out. This has been called the “Great Dying,” but has not been explained. So far there is no evidence of an asteroid impact at that time. The second greatest break is the one that we have discussed, 65 My ago, caused by an asteroid impact.
Geologists have divided the eras into shorter intervals called Periods, such as the Jurassic Period, noted for its large dinosaurs. These Periods are also defined by breaks in the fossil record, smaller than the breaks between eras. Many species went extinct during these breaks, but not as many as in the breaks between the Eras. Evidence for impacts, smaller than the one 65 My ago, has been found at some of the breaks, but not at others.
Dinosaur Egg Fossils That Tell A Tale
Researchers collected over 1,000 dinosaur eggshell samples from a 150-m-thick stratigraphically continuous fossil-rich sequence in the Shanyang Basin of central China, which is one of the most abundant dinosaur areas from Late Cretaceous sequence. The researchers have analyzed over 5,500 Rock samples using computer modelling to accurately date them.
The study revealed a decline in dinosaur diversity in the region and around 1000 dinosaur egg fossils came from three main species – Macroolithus yaotunensis, Elongatoolithus elongatus, and Stromatoolithus pinglingensis. The fossils also showed that large-bodied, long-necked dinosaurs also lived there in the same era around 66.4 and 68.2 million years ago.
Hence, the low number of dinosaur species for the last few million years is expected to result from global climate fluctuations and massive volcanic eruptions. ?The end-Cretaceous catastrophic events, such as the Deccan Traps and bolide impact, probably acted on an already vulnerable ecosystem and led to nonavian dinosaur extinction,? the study said.
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Did A 2nd Asteroid Help Kill The Dinosaurs
The ocean floor is famously less explored than the surface of Mars. And when our team of scientists recently mapped the seabed and ancient sediments beneath, we discovered what looks like an asteroid impact crater.
Intriguingly, the crater, named Nadir after the nearby volcano Nadir Seamount, is of the same age as the Chicxulub impact, which occurred when a huge asteroid struck Earth at the end of the Cretaceous period, around 66 million years ago. The impact wiped out the dinosaurs and many other species.
The peer-reviewed journal Science Advances the finding on August 17, 2022. It raises the question of whether the crater might be related to Chicxulub in some way. If confirmed, it would also be of huge general scientific interest. It would be one of a very small number of known marine asteroid impacts and provide unique new insights into what happens during such a collision.
What Happened To The Dinosaur
The enormous chunk of space rock is thought to have vaporized into millions of pieces when it hit the earth.
These fragments then vaporized into clouds of debris, which were carried by winds around the globe.
When the dust settled, some of the particles formed new meteorites.
Some of the debris landed on land and created mountains and volcanoes.
Others fell back down to earth and buried themselves deep underground.
Still, others remained suspended in the upper atmosphere where they could not escape.
These stratospheric meteors eventually burned up in the atmosphere.
Had the impact occurred moments later, the dinosaur killer may not have been nearly as devastating.
If it had hit deeper water rather than the shallow coastal waters of the Mexican peninsula, there would have been far less vaporized rock, and the climate devastation would have been greatly reduced.
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Asteroid Impact Not Volcanic Activity Killed The Dinosaurs Study Finds
It was the asteroid all along.
An asteroid impact, not volcanic activity, killed the dinosaurs, a new study finds.
For decades, scientists have gone back and forth over exactly what caused a mass extinction event 66 million years ago, which destroyed about 75% of all life on Earth, including all of the large dinosaurs. Some have thought that volcanic activity could be to blame, but one new study shows that a giant asteroid impact was the prime culprit.
Scientists have known that the impact, which created the massive Chicxulub impact crater , was a major contributing factor to this extinction event. But volcanic activity happening at around the same time has raised questions over which could have been the main factor which changed conditions on our planet that led to the demise of Earth’s creatures.
In a new study, researchers from Imperial College London, the University of Bristol and University College London have shown that the asteroid impact, not volcanic activity, was the main reason that about 75% of life on Earth perished at that time, and it did so by significantly interfering with Earth’s climate and ecosystems.
With these models, the team found that the giant asteroid hitting our planet would have released tremendous amounts of gas and particles into Earth’s atmosphere, blocking out the sun for years on end. This effect would have created a sort of semi-permanent winter on Earth, making the planet unlivable for most of its inhabitants.
List Of Impact Craters On Earth
|This article appears to contradict itself on the sizes of craters. Please see the talk page for more information.|
|Map all coordinates using:OpenStreetMap|
To keep the lists manageable, only the largest craters within a time period are included. Alphabetical lists for different continents can be found under Craters by continent below.
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