In the Oct. issue of Earth and Planetary Science Letters, vol. 643:
Zhang, T. A. Liao, S-Y. Wu, R-C. et al. L-chondrite body breakup in Ordovician strata in China – A time … Art. 118891 .2024.118891
We’re tracing the history of Earth, including the scars. Impact craters are clearly scars, but this also includes dust/micrometeorites. Not very impacty. In particular, fossil meteorites (directly preserved examples, or remnants of meteorites) show a peak in the Ordovican era, ~460 million years ago. It appears a body, whose makeup matches the L-chondrite meteorites, was in near-Earth space, then suffered some breakup. So ~460 million years ago, and to an extent continuing today, it’s been raining L-chondrite material, we think. How well do we know this, or are there alternate explanations? If so, what happened, how, and why? Zhang et al. think they’re onto something. For one, a massive dust cloud can affect the weather; so might the nitrous oxides from very-high-speed falling bodies.