9CaKrnQhYo4 world.huanqiu.comgallery至少约22亿年!地球最古老陨石坑或助地表走出冰河期/e3pmh22ph/e3pn6efsl1579820700000责编:刘艳君中新网157982070000011[]{"audio":{"members":[]},"gallery":{"members":[{"desc":" 据报道,《自然通讯》期刊21日刊登的一份研究称,澳大利亚的亚拉布巴陨石坑(Yarrabubba crater)是世上已知最古老陨石坑,年龄至少约22亿年,撞击当时可能还造成“全球大解冻”,让地表走出冰河期。图片来源:NASA官网\r\r","height":694,"id":"4ec181f4ddcb915a5a811a085c0043a7","mime":"image\/jpeg","size":110,"url":"\/\/himg2.huanqiucdn.cn\/attachment2010\/2020\/0124\/20200124070612804.jpg","width":930},{"desc":" 据报道,亚拉布巴陨石坑已被发现近20年。经历长期侵蚀风化,现已变得非常平坦,无法用肉眼观察撞击结构和原始大小。科学家此前根据磁场数据推估,整个陨石坑直径应有约70公里。图片来源:NASA官网\r\r","height":620,"id":"1bf981cdcd60b7c42c538095a71ecad3","mime":"image\/jpeg","size":105,"url":"\/\/himg2.huanqiucdn.cn\/attachment2010\/2020\/0124\/20200124070612187.jpg","width":930},{"desc":" 澳洲科廷大学(Curtin University)研究团队利用同位素分析法,发现陨石坑岩石含有的细小“锆石和独居石(monazite)”,经小行星撞击造成的“冲击”再结晶,产生如树木年轮的结构。研究指出,独居石晶体含有微量铀,因铀会以恒定速度衰变至铅,能借此估算时间流逝。图为锆石晶粒的图像。图片来源:NASA官网\r","height":465,"id":"7e439167d657bfa799f92f0e18f39cae","mime":"image\/jpeg","size":60,"url":"\/\/himg2.huanqiucdn.cn\/attachment2010\/2020\/0124\/20200124070612572.jpg","width":930}]},"video":{"members":[]}}