Here\u2019s what you\u2019ll learn when you read this story:<\/p>\n
Because of Earth\u2019s weathering climate and shifting tectonics, impact craters regularly disappear from the Earth\u2019s geologic record.<\/p>\n<\/li>\n
Scientists in China found an impact crater that formed during the current epoch, and at 900 meters wide it\u2019s three times larger than the previous record holder.<\/p>\n<\/li>\n
The impact likely occurred less than 10,000 years ago and was caused by a 30-meter-wide asteroid traveling at roughly 45,000 miles per hour.<\/p>\n<\/li>\n<\/ul>\n
When it comes to impact craters<\/a>, the rest of the solar system is an open book. Take a glimpse at the surface of other rocky bodies, such as Mars<\/a> or Mercury<\/a>, and you\u2019ll find a rich tableau of past astronomical trauma across billions of years. Earth, on the other hand, is a much harder read, due to its erosion-driving climate and rumbling plate tectonics. While some of Earth\u2019s biggest blow ups can still be identified\u2014its ancient run-in with its protoplanet sibling<\/a>, Theia, and the dino-killer Chicxulub<\/a> being prime examples\u2014they still require serious effort, and lesser impacts from Earth\u2019s early days have been long lost to the tides of history.<\/p>\n Today, Earth\u2019s atmosphere helps burn up many would-be impacts before they do devastating damage. But the Holocene<\/a> (our current geologic epoch) still contains more than a few serious impacts, with the largest being a 300-meter Macha crater in Russia\u2014that is, until now. A new study published by a team of Chinese scientists in the journal Matter and Radiation at Extremes<\/a> details the discovery of a new impact crater located in Guangdong Province in southern China, which at at 900 meters is three times larger than the Macha crater.<\/p>\n \u201cThis discovery shows that the scale of impacts of small extraterrestrial objects on the Earth in the Holocene is far greater than previously recorded,\u201d Center for High Pressure Science and Technology Advanced Research in Shanghai\u2019s Ming Chen, the lead author of the study, said in a press statement<\/a>.<\/p>\n Despite being discovered in a region known for heavy rain, monsoons, and high humidity\u2014typically not an environment conducive to geologic preservation\u2014the crater appeared clearly defined. Therefore, scientists could confirm that it was, in fact, a meteorite strike and not a cometary one (which would leave behind a much larger crater).<\/p>\n The tell-tale sign of an impact crater lies in what\u2019s called \u201cplanar deformation features,\u201d microscopic signatures embedded in quartz grains that geologists have identified as indicators of an impact event.<\/p>\n \u201cOn the Earth, the formation of planar deformation features in quartz is only from the intense shockwaves generated by celestial body impacts, and its formation pressure ranges from 10 to 35 gigapascals, which is a shock effect that cannot be produced by any geological process of the Earth itself,\u201d Chen said in a press statement.<\/p>\n According to the researchers, the Jinlin impact played out something like this: Less than 10,000 years ago or so, a 30-meter wide asteroid traveling around 20 kilometers per second (roughly 45,000 miles per hour) smacked right into a granite hillside. The impact sent granite weathered soil into the air that eventually came to rest around the crater rim. In the north of the rim, where weathered rock was more scarce, the meteorite even dug into the granite bedrock.<\/p>\n Future studies will be needed to precisely date the impact, but by comparing the chemical weathering rate of granite in the rainy, hilly region of Guangdong Province (at about 0.038mm per year) with the size of granite fragments found at the site, scientists suggest that this explosive drama likely took place in early-to-mid Holocene (i.e. less than 10,000 years ago).<\/p>\n The Jinlin impact crater joins a small list (relatively speaking) of only 200 or so confirmed impact craters, though Earth has been pummeled thousands and thousands of times throughout its 4.6-billion-year lifespan. Whether known or unknown, all of these impacts have helped form the planet we all call home<\/a>.<\/p>\n You Might Also Like<\/strong><\/p>\n","protected":false},"excerpt":{"rendered":"Here\u2019s what you\u2019ll learn when you read this story: Because of Earth\u2019s weathering climate and shifting tectonics, impact…\n","protected":false},"author":3,"featured_media":397014,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[84044,188268,1730,188266,188267,159,67,132,68],"class_list":{"0":"post-397013","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-earths-atmosphere","9":"tag-geologic-epoch","10":"tag-impact","11":"tag-impact-craters","12":"tag-macha-crater","13":"tag-science","14":"tag-united-states","15":"tag-unitedstates","16":"tag-us"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/115593652759921824","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/397013","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=397013"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/397013\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/397014"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=397013"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=397013"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=397013"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}