A catastrophic asteroid shower hit Earth & moon 800 million years ago
The impact might have triggered the Ice Age.
- A new study examined data on lunar craters to gain a better understanding of ancient impact events on Earth.
- Although scientists know of some ancient impacts on Earth, weather and erosion makes it hard to study impacts that occurred beyond 600 million years ago.
- Studying craters on the moon can provide some clues.
Since Earth formed 4.5 billion years ago, it's been bombarded by countless asteroids, meteors and other space objects. We know of some of the major incidents. The Chicxulub impact crater in Mexico, for example, formed when a meteorite, between 7 and 50 miles in diameter, slammed into the planet 66 million years ago.
But if you rewind further back in history, 600 million years ago, all signs of impacts have been covered up by erosion, volcanoes and other natural resurfacing processes.
The moon is a different story. Without weather and erosion, the 59 large craters on the lunar surface have remained virtually unchanged over the ages. And scientists can study these ancient lunar craters to get a better understanding of the space objects that likely hit Earth in the distant past, before the sands of time concealed the evidence.
Chicxulub impact crater
In a new study published in Nature Communications, a team of researchers examined data collected by Japanese Space Agency's lunar orbiter Kaguya. The team determined that a massive asteroid shower hit the Earth-Moon system about 800 million years ago, when Earth's early multicellular animals were just undergoing their first splits.
This catastrophic event likely occurred after an asteroid 62 miles in diameter was disrupted and struck both the moon and Earth. The total mass of the shower was far greater than that which created the Chicxulub crater, and it might've triggered the ice age, according to the researchers.
Eight lunar craters that were likely formed simultaneously.
Terada et al.
"...it is not strange that an asteroid shower 800 million years ago might have triggered the Ice age, because a total mass flux 800 million years ago is 10 -100 times larger than those of Chicxulub impact and/or a meteoroid shower 470 million years ago," Kentaro Terada, lead study author and professor at Osaka University in Japan, told CNN.
By measuring the density of the smaller lunar craters that lie inside bigger ones, the team determined that eight of the moon's 59 craters likely formed at the same time. NASA data supports this hypothesis. In 1969, the Apollo 12 mission collected lunar samples ejected from the 58-mile-wide Copernicus crater. The samples were estimated to be 800 million years old.
Terada et al.
Although no complex animals would've been around to witness the impact on Earth, the asteroid shower could've brought elements to Earth that "influenced marine biogeochemical cycles" and caused "severe perturbations to Earth's climate system and the emergence of animals," the authors wrote.
Catastrophic impacts like these are extremely rare, occurring only once every 100 million years or so. In modern history, the most recent major impact was likely the Tunguska event, which occurred in Eastern Russia in 1908 when a meteor blitzed through the atmosphere and exploded, leveling some 80 million trees over 830 square miles, possibly killing several people.
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- The fine structure constant has mystified scientists since the 1800s.
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- Relativity, electromagnetism and quantum mechanics are unified by the number.
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A 2020 study published in the journal of Psychological Science explores the idea that fake news can actually help you remember real facts better.
- In 2019, researchers at Stanford Engineering analyzed the spread of fake news as if it were a strain of Ebola. They adapted a model for understanding diseases that can infect a person more than once to better understand how fake news spreads and gains traction.
- A new study published in 2020 explores the idea that fake news can actually help you remember real facts better.
- "These findings demonstrate one situation in which misinformation reminders can diminish the negative effects of fake-news exposure in the short term," researchers on the project explained.
Previous studies on misinformation have already paved the way to a better understanding<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDU1NzQ4NC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxNjE2Mjg1Nn0.hs_xHktN1KXUDVoWpHIVBI2sMJy6aRK6tvBVFkqmYjk/img.jpg?width=1245&coordinates=0%2C800%2C0%2C823&height=700" id="fc135" class="rm-shortcode" data-rm-shortcode-id="246bb1920c0f40ccb15e123914de1ab1" data-rm-shortcode-name="rebelmouse-image" alt="fake news concept of misinformation and fake news in the media" />
How does misinformation spread?
Credit: Visual Generation on Shutterstock<p><strong>What is the "continued-influence" effect?</strong></p><p>A challenge in using corrections effectively is that repeating the misinformation can have negative consequences. Research on this effect (referred to as "continued-influence") has shown that information presented as factual that is later deemed false can still contaminate memory and reasoning. The persistence of the continued-influence effect has led researchers to generally recommend avoiding repeating misinformation. </p><p>"Repetition increases familiarity and believability of misinformation," <a href="https://engineering.stanford.edu/magazine/article/how-fake-news-spreads-real-virus" target="_blank" rel="noopener noreferrer">the study explains</a>.</p><p><strong>What is the "familiarity-backfire" effect?</strong></p><p>Studies of this effect have shown that increasing misinformation familiarity through extra exposure to it leads to misattributions of fluency when the context of said information cannot be recalled. <a href="https://journals.sagepub.com/doi/10.1177/0956797620952797#" target="_blank" rel="noopener noreferrer">A 2017 study</a> examined this effect in myth correction. Subjects rated beliefs in facts and myths of unclear veracity. Then, the facts were affirmed and myths corrected and subjects again made belief ratings. The results suggested a role for familiarity but the myth beliefs remained below pre-manipulation levels. </p>