On the pages of the site there are many discussions about what happened on Earth 1000 years ago, 10 thousand years ago. There is complete confusion about who is doing what. And everyone is right as usual. On the one hand, if we don’t know such a “recent” past, how can we know what was there 65 million years ago? Sometimes it seems that we know more about those ancient times. At least quite extensive archaeological research has been done using precise equipment. Or are the dinosaurs fake too?!
So what do scientists report? At the end of the Cretaceous period, i.e. 65 million years ago a huge meteorite fell on planet Earth. It was a planetary catastrophe. Not the first and not the last time. A meteorite that fell near what is now located on the coast of the Mexican Yucatan Peninsula Chicxulub village, left its mark not only in its appearance, but also in the history of the development of life on Earth.
Before this cataclysm, dinosaurs and related reptiles reigned on land, in the air and in the sea. After the catastrophe they became extinct, and mammals and birds took the path of evolutionary development.
The Chicxulub Crater is not a place of legend. It was found in the 1970s, but they did not immediately study it, since the depression was covered with a thick layer of sedimentary rocks. In the 1990s, the crater was examined again, and scientists determined that the date of its formation exactly corresponds to the boundary of the Cretaceous and Paleogene periods.
Dead and survivors
At the site where the Chicxulub meteorite fell, the sky was covered with clouds of dust. Forest fires raged everywhere, adding smoke and soot to the dust. The situation was getting even worse. For several weeks, the sky over the entire globe darkened, the light of the Sun did not penetrate to the surface of the planet, which did not allow plants on land and in the oceans to normally carry out their main function - photosynthesis.
Plants began to die. But they serve as food for herbivores, and these, in turn, feed on predators. Any serious disturbance in the chemical and physical situation on Earth, such as a sharp decrease in illumination or a drop in temperature, instantly affects the flora of the planet. The reverberations of these disturbances reverberated throughout the entire ecosystem.
Probably, after the fall of the meteorite, the microscopic plants of the ocean were the first to die out. Thus, the marine ecosystem collapsed. However, there is evidence that the meteorite only accelerated their death. The seagrass began to die off long before the impact, likely due to major changes in the patterns of ocean currents. On land, it is believed that the meteorite impact not only obscured the Sun, but also caused large-scale fires and acid rain, which caused serious damage to land plants.
A study of rocks at Hell Creek, Montana, showed that more than 75% of plant species in inland North America became extinct after a meteorite impact. It is believed that the most recently emerged flowering plants, as well as some of the plants typical of the Mesozoic era, such as ginkgos and cycads, were hit the hardest. In a short time period after the impact, ferns stood relatively calmly, and in a longer period, conifers quickly recovered. Oddly enough, land plants in the Southern Hemisphere hardly died out, which means that the impact was actually not as catastrophic as some assume.
Gradually, vegetation around the globe began to slowly return to its lost positions. Flowering plants were the best able to take advantage of the situation. Eventually they diversified into a great variety of species, from small grasses to huge trees, and conquered almost every landscape on the globe.
EXTINCTION
This herbivorous dinosaur, Triceratops, was widespread during the Cretaceous period. By the end of the period they were still thriving and abundant. But then they disappeared, like all dinosaurs.
Among marine fauna, the extinction at the end of the Cretaceous was much more widespread than on land. Among the extinct sea creatures were ammonites that lived in the oceans for 300 million years.
The end of the dinosaur era
Many animals did not survive the disaster. The most famous example is dinosaurs and flying pterosaurs. Along with them, giant marine reptiles such as mosasaurs and plesiosaurs disappeared. There is still debate about why dinosaurs became extinct, while many other groups survived despite the disaster. Thus, bony fishes (12% died out), frogs (0%), salamanders (0%), lizards (6%) and placental mammals (14%) almost did not suffer from extinction.
Dinosaurs were not the only reptiles in that era. Before the Chicxulub meteorite struck, 45 families of turtles, crocodiles, lizards and snakes lived on Earth. Turtles and crocodiles suffered significantly, however, like plants, those who survived soon adapted to the new conditions.
The initial decline in the number and influence of reptiles contributed to the rapid spread of mammals, although they too suffered mass extinctions. About 20% of the ancient mammal families of the Cretaceous period disappeared.
In total, about 75% of animal species disappeared at the turn of the Cretaceous and Paleogene periods. Many of them were already rare and on the verge of extinction, but scientists have not been able to give a reliable explanation of why some species became extinct while others survived. Some biologists believe that extinction or survival was simply a matter of luck.
http://www.3planet.ru/history/terra/1590.htm
In the case of the death of dinosaurs, the main suspect has emerged, who left evidence at the crime scene - a crater with a diameter of about 180 kilometers. Oddly enough, scientists noticed the trace of a giant asteroid quite recently.
Such a large-scale disaster occurred on the Yucatan Peninsula, the southern tip of Mexico.
The unfortunate incident took place approximately 65 million years before the fall of the Tunguska meteorite, and therefore went unnoticed by wide sections of the world community.
For many years, people did not see the gigantic funnel with a maximum depth of 900 meters, which was also partially hidden by the waters of the Gulf of Mexico of the Atlantic Ocean.
Only in the 1990s its cosmic origin was proven by Canadian scientist Alan Hildebrand. This required detailed ground-based and satellite studies.
If you were in his place, you would probably fuss (photo from bbc.co.uk).
Although, back in 1980, something similar was suggested by the American Nobel laureate physicist Luis Alvarez.
The crater was named Chicxulub, after the name of a poor village located nearby.
Not surprisingly, local residents had no idea that they were walking on the memorial. The height difference across the five kilometers of the outer boundary of the crater is only a few meters.
According to scientists' calculations, the diameter of the asteroid that caused such significant destruction should have been about 10 kilometers. Unless the damage was caused by a passing comet.
The consequences of the collision turned out to be disastrous for all earthly living creatures at the end of the Mesozoic era.
Presumably, gigantic masses of dust rose into the air, obscuring the Sun and preventing plant growth.
The arrows indicate the boundary of the crater “trough” (NASA photo).
The instantaneous evaporation of billions of tons of rock led to climate change on the planet.
Sulfur fumes from the disaster site caused acid rain.
To top it all off, volcanic activity that had died down intensified.
In total, according to various estimates, from 70 to 90 percent of living creatures of that era were ordered to live long. Maybe this is for the best: otherwise we would not see the dominance of mammals and you would not read our article.
By the way, on the territory of Ukraine there is the Boltysh crater with a diameter of 24 km. According to the latest estimates, it was formed at about the same time as Chicxulub, plus or minus a “pathetic” 250 thousand years.
The largest meteorite funnel is located in this circle (photo from bbc.co.uk).
That is, most likely, an asteroid “doublet” took place. Although the Ukrainian heavenly guest was smaller - ten times.
The Chicxulub crater is currently undergoing intensive scientific research. It is planned to drill three wells, with a depth of 700 meters and one and a half kilometers. The cost of the work is estimated at $1.5 billion.
The fact is that the source of the explosion has since long been filled with limestone deposits, the thickness of which in some places reaches one kilometer. The processes of destruction and erosion of limestone rocks caused the formation of voids and drainage wells.
These natural containers were practically used by the disappeared civilization of the Mayan Indians to perform sacrifices.
In-depth research will help restore the original geometry of the funnel.
A chemical analysis of the composition of the rock at the bottom of the drilled wells will make it possible to understand the scale of the environmental disaster that almost buried earthly life, and to examine other evidence that still remains at the “crime scene.”
Free artistic fantasy based on ancient events (photo from home.lanet.lv).
You may ask why we suddenly remembered about the Yucatan collapse, although nothing has really been proven yet. Maybe they wouldn’t have remembered if it weren’t for NASA.
At the very beginning of March 2003, the American agency finally published the results of space photography of the crater surface taken by the Endeavor shuttle back in 2000.
During the 11-day February event, called the Shuttle Radar Topography Mission (SRTM), the shuttle carried out volumetric space imaging of Chicxulub, and at the same time another 80% of the earth's surface.
The study of the results resulted in the processing of eight terabytes of information from 200 billion qualitative measurements of the planetary topography. The whole process took three years, so the Americans only got around to publishing it now.
Very timely, in our opinion, since the investigation
Our beloved blue planet is constantly being hit by space debris, but due to the fact that most space objects burn up or fall apart in the atmosphere, this most often does not pose any serious problems. Even if an object reaches the surface of the planet, it is most often small, and the damage it causes is insignificant.
However, of course, there are very rare cases when something very large flies through the atmosphere, and in this case very significant damage is caused. Fortunately, such falls are extremely rare, but it’s worth knowing about them, if only to remember that there are forces in the Universe that can disrupt people’s everyday lives in a couple of minutes. Where and when did these monsters fall to Earth? Let's look at the geological records and find out:
10. Barringer Crater, Arizona, USA
Arizona apparently couldn't get enough of the Grand Canyon, so about 50,000 years ago it added another tourist attraction when a 50-meter meteorite landed in the northern desert, leaving behind a crater 1,200 meters in diameter and deep. at 180 meters. Scientists believe that the meteorite that created the crater flew at a speed of about 55 thousand kilometers per hour, and caused an explosion about 150 times more powerful than the atomic bomb dropped on Hiroshima. Some scientists initially doubted that the crater was formed by a meteorite, since there is no meteorite itself, but according to modern scientists, the stone simply melted during the explosion, spreading molten nickel and iron throughout the surrounding area.
Although its diameter is not that large, its lack of erosion makes it an impressive sight. Moreover, it is one of the few meteorite craters that look true to its origin, making it a top-notch tourist destination - just as the Universe intended.
9. Lake Bosumtwi Crater, Ghana 
When someone discovers a natural lake whose outline is almost perfectly round, it is quite suspicious. This is exactly what Lake Bosumtwi is, with a diameter of about 10 kilometers and located 30 kilometers southeast of Kumasi, Ghana. The crater was formed by a collision with a meteorite with a diameter of about 500 meters, which fell to Earth about 1.3 million years ago. Attempts to study the crater in detail are quite difficult, since the lake is difficult to reach, it is surrounded by dense forest, and the local Ashanti people consider it a holy place (they believe that touching the water with iron or using metal boats is prohibited, making access to nickel at the bottom of the lake is problematic). Still, this is one of the best-preserved craters on the planet today, and a good example of the destructive power of megarocks from space.
8. Mistastin Lake, Labrador, Canada 
The Mistatin impact crater, located in the Labrador province of Canada, is an impressive 17 by 11 kilometer depression in the earth that formed approximately 38 million years ago. The crater was likely originally much larger, but has shrunk over time due to the erosion it has suffered from the many glaciers that have passed through Canada over the past millions of years. This crater is unique in that, unlike most impact craters, it is elliptical in shape rather than circular, indicating that the meteorite fell at an acute angle rather than flat, as is the case with most meteorite impacts. Even more unusual is the fact that in the middle of the lake there is a small island that may be the central rise of the complex structure of the crater.
7. Gosses Bluff, Northern Territory, Australia
This 142-million-year-old crater with a diameter of 22 kilometers, located in the center of Australia, is an impressive sight from both the air and the ground. The crater was formed by the impact of an asteroid with a diameter of 22 kilometers, which crashed into the Earth's surface at a speed of 65,000 kilometers per hour and created a crater almost 5 kilometers deep. The energy of the collision was approximately 10 to the twentieth power of Joules, so life on the continent faced great problems after this collision. The highly deformed crater is one of the most significant impact craters in the world and never lets us forget the power of one large rock.
6. Clearwater Lakes, Quebec, Canada 
Finding one impact crater is cool, but finding two impact craters next to each other is doubly cool. That's what happened when the asteroid broke into two pieces as it entered Earth's atmosphere 290 million years ago, creating two impact craters on the eastern shore of Hudson Bay. Since then, erosion and glaciers have greatly eroded the original craters, but what remains is still an impressive sight. The diameter of one lake is 36 kilometers, and the second is about 26 kilometers. Considering that the craters were formed 290 million years ago and were subject to severe erosion, one can only imagine how large they were originally.
5. Tunguska meteorite, Siberia, Russia
This is a controversial point, since no parts of the hypothetical meteorite remain, and what exactly fell into Siberia 105 years ago is not entirely clear. The only thing that can be said with certainty is that something large and moving at high speed exploded near the Tunguska River in June 1908, leaving behind fallen trees over an area of 2000 square kilometers. The explosion was so strong that it was recorded by instruments even in the UK.
Because no pieces of meteorite were found, some believe that the object may not have been a meteorite at all, but a small part of a comet (which, if true, would explain the lack of meteorite debris). Conspiracy fans believe that an alien spaceship actually exploded here. Although this theory is completely unfounded and pure speculation, we must admit that it sounds interesting.
4. Manicouagan Crater, Canada 
Manicouagan Reservoir, also known as the "Eye of Quebec", is located in a crater formed 212 million years ago when an asteroid with a diameter of 5 kilometers fell to Earth. The crater with an area of 100 kilometers, which remained after the fall, was destroyed by glaciers and other erosive processes, but at the moment it remains an impressive sight. What is unique about this crater is that nature did not fill it with water, forming an almost perfectly round lake - the crater basically remained dry land, surrounded by a ring of water. A great place to build a castle here.
3. Sudbury Crater, Ontario, Canada 
Apparently, Canada and impact craters are very fond of each other. Singer Alanis Morrisette's birthplace is a favorite place for meteorite impacts - the largest meteorite crater in Canada is located near Sudbury, Ontario. This crater is already 1.85 billion years old, and its dimensions are 65 kilometers long, 25 wide and 14 deep - it is home to 162 thousand people, and is also home to many mining enterprises, which discovered a century ago that the crater is very rich in nickel. for a fallen asteroid. The crater is so rich in this element that about 10% of the world's nickel production comes from here.
2. Chicxulub Crater, Mexico
The impact of this meteorite may have caused the extinction of the dinosaurs, but it is certainly the most powerful asteroid collision in the entire history of the Earth. The impact occurred approximately 65 million years ago when an asteroid the size of a small city crashed into Earth with an energy of 100 teratons of TNT. For those who like precise data, this is approximately 1 billion kilotons. Compare this energy to the atomic bomb dropped on Hiroshima, with a yield of 20 kilotons, and the impact of this collision becomes clearer.
The impact not only created a crater 168 kilometers in diameter, but also caused megatsunamis, earthquakes and volcanic eruptions across the Earth, greatly altering the environment and dooming the dinosaurs (and apparently many other creatures). This vast crater, located on the Yucatan Peninsula near the village of Chicxulub (from which the crater gets its name), can only be seen from space, which is why scientists discovered it relatively recently.
1. Vredefort Dome, South Africa
Although the Chicxulub crater is better known, compared to the 300-kilometer-wide Vredefort Crater in South Africa, it is an ordinary pothole. Vredefort is currently the largest impact crater on Earth. Fortunately, the meteorite/asteroid that fell 2 billion years ago (its diameter was about 10 kilometers) did not cause significant harm to life on Earth, since multicellular organisms did not yet exist at that time. The collision undoubtedly greatly changed the Earth's climate, but no one noticed it.
At the moment, the original crater is heavily eroded, but from space its remains look impressive and are a great visual example of how scary the Universe can be.
Many researchers are of the opinion that dinosaurs died as a result of the fall of a large meteorite almost 66 million years ago. True, there are experts who claim that he simply finished off the ancient lizards, who began to die out before the fall of the space “aliens.”
Nevertheless, the very fact of the meteorite fall is naturally not disputed by scientists. Moreover, some experts are carefully studying the impact crater near the Yucatan Peninsula, which is somehow associated with the extinction of dinosaurs.
The impact crater is called Chicxulub (Mayan word for "demon of ticks"). Last spring, an international team of researchers drilled a well in one part of the Chicxulub crater - to a depth of 506 to 1335 meters under the seabed (the crater is partially submerged under the waters of the Gulf of Mexico). And thanks to this, not so long ago scientists were able to determine sea level measurements from prehistoric times.
Now experts have extracted rock samples from under the Gulf of Mexico that were hit by that same meteorite. This material helped scientists obtain vital details that allow them to better understand the ancient event. It turned out that a giant asteroid could not have found a worse place to land on our planet.
The shallow sea covers the “target”, which means that as a result of the fall of the space “alien”, colossal volumes of sulfur released from the mineral gypsum were released into the atmosphere. And following the immediate firestorm that occurred after the meteorite fell, a long period of “global winter” began.
Researchers say that if the intruder had fallen in a different location, the outcome could have been completely different.
"The irony of history is that it wasn't the size of the meteorite or the scale of the explosion that caused the disaster, but where it fell," says Ben Garrod, co-host of The Day the Dinosaurs Died. Day The Dinosaurs Died with Alice Roberts), in which the scientists’ findings were presented.
In particular, experts say, if the asteroid, which was supposedly 15 kilometers across, had reached the Earth a few seconds earlier or later, it would have landed not in shallow coastal waters, but in the deep ocean. A fall in the Atlantic or Pacific Oceans would have resulted in much less rock—including deadly calcium sulfate—evaporating.
The clouds would be less dense, so the sun's rays could make their way to the Earth's surface. Accordingly, the consequences that occurred could have been avoided.
“In that cold, dark world, food ran out in the ocean within one week, and then on land a short time later. Without a food source, the mighty dinosaurs had little chance of survival,” notes Garrod.
It is noted that the core (rock sample) was extracted from depths of up to 1300 meters during drilling in the crater area. The deepest parts of the rock were mined in the so-called "peak ring". By analyzing the properties of this material, the authors of the work hope to reconstruct in more detail the picture of the fall of the asteroid and the subsequent changes, the BBC News website reports.
Researchers, by the way, found that the energy released during the formation of the crater was equal to the energy of approximately ten billion atomic bombs, similar to the one dropped on Hiroshima. Researchers are also studying how the site began to come back to life several years after the meteorite struck.
Let us add that some experts are inclined to believe that, for example, dark matter is to blame for the extinction of dinosaurs, and microbes are also under the “gun.” It is possible that volcanoes also contributed.
Chicxulub Crater is the largest meteorite crater on Earth, located in the northwestern part of the Yucatan Peninsula and at the bottom of the Gulf of Mexico.
Chicxulub Crater Location (Dementia) Chicxulub Coast (Karyn Christner)
Chicxulub Crater is a large meteorite crater in the northwestern part of the Yucatan Peninsula and at the bottom of the Gulf of Mexico. With a diameter of approximately 180 km, it is one of the largest known impact craters on Earth. Chicxulub is located approximately half on land and half under the waters of the gulf.
Due to the gigantic size of the Chicxulub crater, its existence cannot be determined by eye. Scientists discovered it only in 1978, and quite by accident, while conducting geophysical research at the bottom of the Gulf of Mexico.
Location of the Chicxulub crater (Dementia)
During these studies, a huge underwater arc with a length of 70 km, shaped like a semi-circle, was discovered.
According to gravitational field data, scientists have found a continuation of this arc on land, in the north-west of the Yucatan Peninsula. When they come together, the arcs form a circle whose diameter is approximately 180 km.
The impact origin of the Chicxulub crater was proven by the gravitational anomaly inside the ring-shaped structure, as well as by the presence of rocks characteristic only of impact-explosive rock formation. This conclusion is also confirmed by chemical studies of soils and detailed satellite imaging of the area. So there is no longer any doubt about the origin of the huge geological structure.
Consequences of a meteorite fall
It is believed that the Chicxulub crater was formed by the fall of a meteorite at least 10 kilometers in diameter. According to available calculations, the meteorite moved from the southeast at a slight angle. Its speed was about 30 kilometers per second.
Chicxulub Coast (Karyn Christner)
The fall of this giant cosmic body occurred approximately 65 million years ago, at the turn of the Cretaceous and Paleogene periods. Its consequences were truly catastrophic and had a profound impact on the development of life on our planet.
The power of the meteorite impact exceeded the power of the atomic bomb dropped on Hiroshima by several million times.
Immediately after the fall, a huge ridge formed surrounding the crater, the height of which could reach several thousand meters.
However, it was soon destroyed by earthquakes and other geological processes. The impact caused a powerful tsunami; It is assumed that the wave height was between 50 and 100 meters. The waves traveled far into the continents, destroying everything in their path.
A shock wave with a high temperature and causing forest fires passed around the Earth several times. Tectonic processes and volcanism have intensified in different parts of our planet.
As a result of numerous volcanic eruptions and forest burning, huge amounts of dust, ash, soot and gases were released into the Earth's atmosphere. The raised particles caused the effect of a volcanic winter, when most of the solar radiation is blocked by the atmosphere and global cooling sets in.
Such drastic climate changes, along with other negative consequences of the impact, were disastrous for all life on Earth. There was not enough light for plants to carry out photosynthesis, causing the oxygen content in the atmosphere to be greatly reduced.
Due to the disappearance of a significant part of the vegetation cover of our planet, animals that lacked food began to die out. It was as a result of these events that dinosaurs became completely extinct.
Cretaceous-Paleogene extinction
The fall of this meteorite is the most convincing cause of the Cretaceous-Paleogene mass extinction. The version of the extraterrestrial origin of these events took place even before the discovery of the Chicxulub crater.
It was based on the abnormally high content of such a rare element as iridium in sediments that are about 65 million years old. Since high concentrations of this element were found not only in the sediments of the Yucatan Peninsula, but also in many other places on Earth, it is possible that a meteor shower occurred at that time. There are other versions, however, they are less widespread.
At the boundary of the Cretaceous and Paleogene, all the dinosaurs, marine reptiles and flying dinosaurs that reigned on our planet in the Cretaceous period became extinct.
Existing ecosystems were completely destroyed. In the absence of large lizards, the evolution of mammals and birds, the biological diversity of which greatly increased in the Paleogene, accelerated significantly.
It can be assumed that other mass extinctions of species throughout the Phanerozoic were also caused by falls of large meteorites.
Existing calculations show that impacts of celestial bodies of this size on Earth occur approximately once every hundred million years, which roughly corresponds to the time intervals between mass extinctions.
Documentary film "Asteroid Fall"