What implications do younger Earth and Moon have on Late Heavy Bombardment genesis hypotheses? The Late Heavy Bombardment (LHB) or the Lunar Cataclysm is when the inner solar system, including the Earth and the Moon, underwent multiple and sustained heavy impacts early in their history (around 3.7-4 billion years ago). This event formed many of the major impact scars we see on the Moon, (presumably as well as much of the impacts observed on Mars and Mercury). Two main theories are based on perturbations in either the Kuiper Belt, or in a primordial larger asteroid belt.

What implications would a younger Earth and Moon, discussed in "Moon and Earth may be younger than originally thought" (Lars Borg et al., 2011) have on hypotheses on what caused the LHB?
From the article: "In fact, its age may be 4.36 billion years old." This is still older than the estimated age of the Late Heavy Bombardment, so it wouldn't affect that hypothesis much. In fact, it may actually help the hypothesis, as it means the Moon would have more of its interior molten (though probably not by much). It's suggested that the magma from underneath the crust filled the lunar mare after the giant impacts through fissures in the crust. (Wikipedia)