At my university we had access to lead bricks (roughly 5x10x20 cm) used for radiation shielding at a small accelerator. One Friday evening it became at great id

At my university we had access to lead bricks (roughly 5x10x20 cm) used for radiation shielding at a small accelerator. One Friday evening it became at great idea to take one of those to the seventh floor and let it fall onto the lawn below. One of the most underwhelming experiences ever: there was hardly any indentation in the moist soil. Bullets go really fast. (I realize you said "drop from space" which would be a completely different matter of course, so I suspect you have realized this without experiments.)