英属哥伦比亚大学及来自巴黎、布鲁塞尔和维也纳的研究人员通过分析白垩纪-古近纪撞击事件遗留材料中的镍同位素，确定了6600万年前杀死恐龙的小行星属于CO型碳质球粒陨石[1]。这颗来自太阳系外部地区的陨石直径约为10至15公里[1]，以64,000公里/小时的速度撞击地球[1]，在现今位于墨西哥尤卡坦半岛下方形成了希克苏鲁伯陨石坑[1]。此次撞击引发了约75%物种的灭绝[1]，包括所有非鸟类恐龙。
研究表明，陨石本身的硫磺含量可能并非灾难的主要驱动因素，相反是撞击产生的大量细微碎屑进入大气层才是关键因素[1]。CO型陨石在地球采集的陨石中极为罕见，仅占碳质陨石的约5%[1]，且其硫含量远低于其他陨石类型[1]。这一研究成果已发表于《Science Advances》期刊[1]。
Researchers from the University of British Columbia, Paris, Brussels, and Vienna have determined that the asteroid responsible for the extinction of dinosaurs was a rare carbonaceous chondrite of the CO type.[1] By analyzing nickel isotopes in material left behind from the Cretaceous-Paleogene impact event, the international team established the precise composition of the space rock that struck Earth 66 million years ago.[1] The impact triggered the extinction of approximately 75% of all species on the planet, including all non-avian dinosaurs.[1]
The meteorite, which measured between 10 and 15 kilometers in diameter, collided with Earth at a speed of approximately 64,000 kilometers per hour.[1] The impact created the Chicxulub crater, now located beneath Mexico's Yucatan Peninsula.[1] Contrary to previous assumptions, the research suggests that the sulfur contained within the meteorite itself was not the primary driver of the catastrophic consequences; rather, the vast quantity of fine debris ejected into the atmosphere during the collision proved to be the decisive factor.[1] CO-type carbonaceous chondrites represent only a small fraction of meteorites collected on Earth, accounting for approximately 5% of all carbonaceous meteorites, and contain significantly lower sulfur levels compared to other meteorite types.[1] The findings were published in the journal Science Advances.[1]