近日，法国蔚蓝海岸大学的Chrysa Avdellidou及其研究团队取得一项新进展。经过不懈努力，他们利用顽辉石陨石测定太阳系巨行星轨道不稳定性的年代。相关研究成果已于2024年4月19日在国际权威学术期刊《科学》上发表。

在这项研究中，研究人员通过动力学模拟证实，轨道不稳定性将类地行星区域的星子碎片植入小行星主带。他们利用陨石数据进一步表明，植入发生在太阳系开始形成后大于 60Myr（百万年）。结合先前从木星特洛伊小行星研究中获得的上限，研究人员得出结论：轨道不稳定性发生在太阳系形成开始后的60至100Myr之间。

值得注意的是，形成月球的巨大撞击事件也发生在这个时间范围内，因此可能与巨行星的不稳定性存在关联。

据悉，太阳系的巨行星原本是在紧凑的轨道上形成的。然而，由于轨道的不稳定性，这些行星逐渐迁移至现今更宽的轨道结构。至于这种不稳定性的确切发生时机，目前仍难以确定。

附：英文原文

Title: Dating the Solar System’s giant planet orbital instability using enstatite meteorites

Author: Chrysa Avdellidou, Marco Delbo’, David Nesvorny, Kevin J. Walsh, Alessandro Morbidelli

Issue&Volume: 2024-04-19

Abstract: The giant planets of the Solar System formed on initially compact orbits, which transitioned to the current wider configuration by means of an orbital instability. The timing of that instability is poorly constrained. In this work, we use dynamical simulations to demonstrate that the instability implanted planetesimal fragments from the terrestrial planet region into the asteroid main belt. We use meteorite data to show that the implantation occurred >60 million years (Myr) after the Solar System began to form. Combining this constraint with a previous upper limit derived from Jupiter’s trojan asteroids, we conclude that the orbital instability occurred 60 to 100 Myr after the beginning of Solar System formation. The giant impact that formed the Moon occurred within this range, so it might be related to the giant planet instability.

DOI: 10.1126/science.adg8092

Source: https://www.science.org/doi/10.1126/science.adg8092