The so-called Late Heavy Bombardment (LHB)—when comets and asteroids are thought to have pummeled Earth, the moon, and other inner bodies of the solar system—may have lasted longer than once thought.rnOne explanation for the LHB, thought to have lasted between 4.1 billion and 3.8 billion years ago, is that migration of gas giant planets sent objects in the asteroid belt zooming toward the center of the solar system. Now, in one of two new studies in Nature this week, researchers suggest that the LHB was prolonged by later impactors that came from a largely extinct belt of asteroids known as the E belt.rnRocks from lunar craters have provided much of the evidence for the LHB, but in the second Nature paper, scientists examining Earth-based evidence also found support for a longer onslaught.
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