近日，美国麻省理工学院的M. Marsset及其研究团队取得一项新进展。经过不懈努力，他们证实马萨利亚小行星家族是普通L球粒陨石的起源。相关研究成果已于2024年10月16日在国际权威学术期刊《自然》上发表。

该研究团队提供了光谱观测和动力学证据，表明马萨利亚碰撞族群是这一灾难性事件唯一合理的来源，也是当今地球上最丰富的陨石类别。这一小行星族群位于内带低倾角轨道上，恰好与观测到的类似L球粒陨石的近地天体以及集中在1.4°倾角的行星际尘埃分布相吻合。

据悉，对中奥陶纪石灰岩中的微陨石及地球上撞击坑的研究表明，约4.66亿年前，地球遭遇了大量普通L球粒陨石物质的撞击，这可能是导致奥陶纪冰期及生物多样性重大转变的根源。此次大规模撞击很可能是由主带内一个大型小行星的解体所引起的。目前，源自此次解体的物质仍占据陨石坠落的主导地位（占所有陨石坠落的20%以上）。

附：英文原文

Title: The Massalia asteroid family as the origin of ordinary L chondrites

Author: Marsset, M., Vernazza, P., Bro, M., Thomas, C. A., DeMeo, F. E., Burt, B., Binzel, R. P., Reddy, V., McGraw, A., Avdellidou, C., Carry, B., Slivan, S., Polishook, D.

Issue&Volume: 2024-10-16

Abstract: Studies of micrometeorites in mid-Ordovician limestones and impact craters on Earth indicate that our planet witnessed a massive infall of ordinary L chondrite material about 466 million years ago that may have been at the origin of an Ordovician ice age and major turnover in biodiversity. The breakup of a large asteroid in the main belt is the likely cause of this massive infall. Currently, material originating from this breakup still dominates meteorite falls (>20% of all falls). Here we provide spectroscopic observations and dynamical evidence that the Massalia collisional family is the only plausible source of this catastrophic event and the most abundant class of meteorites falling on Earth today. This family of asteroids is suitably located in the inner belt, at low-inclination orbits, which corresponds to the observed distribution of L-chondrite-like near-Earth objects and interplanetary dust concentrated at 1.4° .

DOI: 10.1038/s41586-024-08007-6

Source: https://www.nature.com/articles/s41586-024-08007-6