Шинэ судалгаагаар 66 сая жилийн өмнө Дэлхий дээр унаж, үлэг гүрвэлийн мөхлийг авчирсан Чиксулуб солир нь нарийн төвөгтэй сансрын биет байж, нарны аймгийн алслагдсан хэсгээс гаралтай болохыг эрдэмтэд тогтоожээ.
Эрдэмтэд 66 сая жилийн өмнө Мексикийн Юкатаны хойгт үүссэн Чиксулуб кратерийн орчмоос үлдсэн шинэхэн хурдас дахь никелийн изотопийг өндөр нарийвчлалтайгаар судалсан байна. Уг мөргөлдөөний үеэр 10-аас 15 километр өргөнтэй, цагт 64,000 километрийн хурдтай яваа аварга том солир бараг бүхлээрээ ууршиж алга болсон тул судлаачид дэлхий даяар тархсан шаварлаг давхаргад үлдсэн өчүүхэн төдий материалыг ашиглан химийн шинж чанарыг нь шинжилжээ. Шинжилгээний үр дүнд уг солир нь дэлхий дээр олддог бүх солируудын ердөө 5 хүрэхгүй хувийг эзэлдэг нүүрстөрөгчит хондритын Ornans төрөлд хамаарах маш ховор CO хондрит болох нь батлагдсан байна.
Vrije Universiteit болон Британскийн Колумбийн их сургуулийн судлаач Филипп Клаейс энэхүү солир нь нарны аймгийн анхдагч материалуудын нэг бөгөөд нүүрстөрөгч, цайр, ус, ялангуяа хүхрийн агууламж багатай болохыг тэмдэглэжээ. “Science Advances” сэтгүүлд нийтлэгдсэн уг судалгаа нь дэлхийн түүхэн дэх мөхлийн ерөнхий дүр зургийг өөрчлөхгүй ч уг солирын агуулдаг хүхэр нь дэлхийн хэмжээний өөрчлөлтийг үүсгэгч гол хүчин зүйл байсан гэх таамгийг үгүйсгэж байна. Үүний оронд мөргөлдөөний улмаас агаар мандалд тархсан асар их хэмжээний нарийн ширхэгтэй тоос шороо нь экосистемийн сүйрэлд гол нөлөө үзүүлсэн болохыг судлаачид онцолжээ.
Энэхүү анхдагч бөгөөд ховор объект нь бархасбадийн ойролцоох солирын бүслүүрийн зах хэсэг эсвэл нарны аймгийн алслагдсан зах хязгаараас гаралтай байж болзошгүй гэж эрдэмтэд үзэж байна. Нарны аймгийн алс холын бүсээс ийм ховор сансрын биет Дэлхийтэй мөргөлдсөн нь тухайн үеийн амьдрал, ялангуяа үлэг гүрвэлүүдийн хувьд маш том азгүйтэл байсныг судлаачид тэмдэглэжээ.
Дэлгэрэнгүйг эх сурвалжаас харах
↓Эх сурвалжийг нээх ↓
The asteroid linked to the extinction of the dinosaurs was not an ordinary space rock. New research suggests that the Chicxulub impactor belonged to a rare group of primitive meteorites called CO chondrites, revealing that the object that changed life on Earth came from an unusual part of the solar system.
Scientists made the discovery by studying nickel isotopes preserved in the thin layer of material left behind after the impact 66 million years ago. The massive asteroid struck near today’s Yucatán Peninsula in Mexico, creating the Chicxulub crater and triggering the event that ended the reign of non-avian dinosaurs. The impactor was estimated to be between 10 and 15 kilometers across and hit Earth at roughly 64,000 km/h.
Studying the object has been difficult because the asteroid was almost completely destroyed during the collision. Only a tiny amount of material survived inside the global clay layer created by the impact, leaving scientists with limited evidence to identify where the asteroid came from.
A Rare Asteroid Hidden In Earth’s Geological Record
Researchers analyzed samples from the thin layer of debris spread around the planet after the Chicxulub impact. Using high-precision measurements of nickel isotopes, they compared the chemical signature of the remaining material with known meteorite groups.
The results matched carbonaceous chondrites of the Ornans type, also known as CO chondrites. These meteorites are extremely rare among samples collected on Earth. Carbonaceous chondrites represent only around 5% of known meteorites, and CO chondrites make up only a small fraction of that group.
“These are definitely not like the typical meteors you find in museum collections,” said Professor Philippe Claeys, a researcher at Vrije Universiteit and the University of British Columbia.
According to Claeys, CO chondrites are among the most primitive materials found in the solar system. They contain lower amounts of volatile elements, including carbon, zinc, water, and particularly sulfur, compared with many other meteorite classes.
The discovery suggests that the asteroid responsible for the dinosaur extinction belonged to a rare category of ancient space material rather than a more common type of asteroid.
The Dust Cloud Was Likely the Main Factor
The study, published in Science Advances, does not change the overall picture of the extinction event. The Chicxulub impact remains linked to the collapse of ecosystems and the disappearance of many species at the end of the Cretaceous period.
The new results mainly affect the debate over the asteroid’s chemical contribution. Since CO chondrites contain much less sulfur than other meteorites, researchers say sulfur from the asteroid itself was less likely to have been the main factor behind the global changes.
“It doesn’t alter our theory of what caused the extinction event, but it makes it less likely that sulfur contained in the impactor was the smoking gun,” Professor Claeys said.
Instead, the researchers point to the huge amount of fine debris released into the atmosphere during the collision. This material came from the violent impact and represented a major part of the aftermath.
The study also highlights how little of the original asteroid remains available for analysis. The researchers explained that almost the entire object vaporized when it hit Earth, leaving only traces preserved in the impact layer.
Where Did the Asteroid Come From?
While researchers have identified the type of asteroid involved, its exact origin remains uncertain. The possible sources include distant debris-rich regions of the outer solar system or the outer area of the asteroid belt near Jupiter.
The asteroid’s arrival was an extremely rare event. A primitive object from a distant region of space traveled across the solar system before colliding with Earth and creating a crater now buried beneath the Yucatán Peninsula. Professor Claeys added that:
“Being impacted by such a rare, distant projectile really underscores how unlucky the dinosaurs were.”
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