尤卡坦半岛的陨石大小  
Yucatan meteor size  

西内SINE

我再次引述。
I quoting again.

喷气推进实验室,2003年3月6日:美国宇航局,检索和编辑于2008年11月12日:
Jet Propulsion Laboratory, 3/6/2003: NASA retrieved 11 12 2008:

希克苏鲁伯陨石坑(尤卡坦陨石坑)是否是由彗星或者小行星碰撞而成,目前还没有定论。喷气推进实验室的唐·约曼斯博士说,双方都有各自的说法。约曼斯博士是美国宇航局近地天体计划办公室的负责人。约曼斯说:‘在地球轨道附近的小行星要比彗星多得多,但大多数都比撞击希克苏鲁伯的那颗10公里(6.2英里)的小得多。在那个大小范围,彗星就很多很多了。’
It is unresolved whether [the Yucatan crater] Chicxulub is the result of a collision with a comet or an asteroid. ‘There are arguments on both sides,’ says the Jet Propulsion Laboratory's Dr. Don Yeomans, who manages NASA's Near-Earth Object Program Office. ‘There are far more asteroids in Earth's orbital vicinity than comets,’ says Yeomans, ‘but most are much smaller than the 10-kilometer size (6.2-mile) of the one that hit Chicxulub. When you get to that size range, then comets are about as prevalent.’

我没见过约曼斯博士,这是我读到的。
I haven’t met D. Yeomans, but this is what I read.