Hammer a hole

hammer n. 锤子/v. 锤；hole n. 洞

'Hammer a hole' means that something has so much energy that it created a hole in/on a surface. Hammer一般作名词使用，此处作动词，表示“砸”。

Roughly 66 million years ago, an asteroid pierced the atmosphere and slammed into Earth. It was up to 15 kilometers wide, and hammered a hole in the ground more than ten times that size.

So:

The asteroid created a hole that was at least ______________ in width.

Answer:

150 kilometers