Moon rocks may have misled asteroid bombardment dating

Spike in impacts 3.9 billion years ago may be mathematical mirage, study finds

illustration of LHB

ROCK ON  A heavy bombardment of asteroids might have pounded the moon (illustrated here), Earth and other planets 3.9 billion years ago. But data from moon rocks supporting this event might not be as clear-cut as previously believed. 

Tim Wetherell, Australian National University/Wikimedia Commons (CC BY-SA 3.0

A barrage of rocks hitting the solar system 3.9