Scientists say second killer asteroid may have hit Earth
Scientists are investigating a second possibility. asteroid It hit Earth at about the same time as what is thought to have killed nearly all dinosaur life.
This investigation is related to a small crater recently discovered in the ocean. Researchers say the crater could have been created by a large asteroid.
Scientists have long believed that a large asteroid collided with Earth about 66 million years ago near Mexico’s Yucatan Peninsula. They estimate the impact of the crash to be equivalent to the power of about 10 billion nuclear bombs.
The strike, or collision, is thought to have caused widespread wildfires, earthquakes, giant ocean waves, or tsunamis. is believed to have led to severe cooling.
More than 70% of plants and animals have become extinct due to climate change. All dinosaurs that did not resemble birds became extinct.
The impact created a huge crater about 180 kilometers wide and 900 meters deep.
Researchers say the newly discovered crater found in the North Atlantic is much smaller. The width is about 8.5 kilometers. Buried up to 400 meters below the seafloor off the coast of Guinea in West Africa.
Scientists discovered the crater using seismographs.Such tools are designed to measure earthquakes and pick up other vibration Signals on Earth.
This crater was discovered by Uisdean Nicholson, a geologist at Heriot-Watt University in Edinburgh, Scotland. At the time, Nicholson was working on an ocean mapping project involving the extent of the ocean floor. This kind of diffusion separated the African and American continents over time, leading to the formation of the Atlantic Ocean.
“I interpreted There was a lot of seismic data in my time, but I had never seen anything like this. feature“
Nicholson said the crater has several elements that suggest it may have been created by an asteroid.But he pointed out that researchers need to do more research before that theory can be confirmed. sample.
The team’s findings were recently reported in a published study scientific progress.
Veronica Bray is another member of the research team. She is a planetary scientist at the University of Arizona.Computer used by Bray simulation To predict the impact that such influences will have.
Simulations suggested that the crater was the result of a 400-meter-tall asteroid impacting 500-800 meters of water. She said this likely caused a 900-meter high tsunami and a magnitude 6.5 earthquake.
Bray pointed out that the newly discovered crater would have been much less impactful than the crater that struck Mexico today. But still “Significantly” to local destruction. She said the new discovery makes her wonder if there are more impact craters that scientists haven’t discovered yet.
Nicholson said his team considered the possibility that both impact craters were related. Researchers believe the newly discovered crater may have been formed by the breakup of a parent asteroid.
Sean Gulick is a crater impact expert at the University of Texas at Austin. He called the discovery an “exciting” finding that could lead to further investigation of other possible effects around the same time.
“Despite the impactors that have hit Earth over four billion years, only 200 have been discovered,” Gulick said in a statement. “It is therefore exciting news whenever new potential impacts are discovered, especially in difficult-to-study (marine) environments,” he added.
I’m Brian Lynn.
Bryan Lynn wrote this article for VOA Learning English based on a report from the University of Arizona, Heriot-Watt College. and scientific progress.
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the words of this story
asteroid – n. A rocky object that orbits the sun like a planet
vibration – n. swaying motion
interpretation – v. to explain, to find the meaning of something
Characteristic – n. A typical or distinctive quality that makes a person or thing different from others
sample – na small amount of something that gives you information about what it was taken from
simulation – nthe creation of something that behaves or looks like something real but is not
important – adjectiveimportant or noteworthy
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