A shattered asteroid may have unleashed a long-lasting cosmic barrage that left scars across the inner solar system and possibly changed Earth’s history. A violent asteroid collision may have sent a wave of debris sweeping through the inner solar system about 800 million years ago, potentially affecting Earth, the Moon, and Mars. The event could help explain a mysterious increase in large impacts recorded on the Moon from the same period. “The location of the parent asteroid was key — it broke up on the brink of the gravitational 3:1 mean motion resonance with Jupiter.” Estimates suggest that for every large object that struck the Moon, Earth was hit by roughly twenty objects of a similar or greater size.