Giant planet migration appears widespread among planetary systems in our Galaxy. However, the timescales of this process, which reflect the underlying dynamical mechanisms, are not well constrained, even within the Solar System. As planetary migration scatters smaller bodies onto intersecting orbits, it would have resulted in an epoch of enhanced bombardment in the Solar System’s asteroid belt. Here, to accurately and precisely quantify the timescales of migration, we interrogate thermochronologic data from asteroidal meteorites, which record the thermal imprint of energetic collisions. We present a database of ⁴⁰K–⁴⁰Ar system ages from chondrite meteorites and evaluate it with an asteroid-scale thermal code coupled to a Markov chain Monte Carlo inversion. Simulations require bombardment to reproduce the observed age distribution and identify a bombardment event beginning \(11.{3}_{-6.6}^{+9.5}\, {\mathrm{Myr}}\) after the Sun formed (50% credible interval). Our results associate a giant planet instability in our Solar System with the dissipation of the gaseous protoplanetary disk.

巨大的行星迁移在我们银河系的行星系统中似乎很普遍。然而，这一过程的时间尺度反映了潜在的动力学机制，即使在太阳系内也没有得到很好的限制。当行星迁移将较小的天体分散到相交的轨道上时，这将导致太阳系小行星带进入一个增强轰击的时代。在这里，为了准确和精确地量化迁移的时间尺度，我们询问小行星陨石的热年代学数据，这些数据记录了高能碰撞的热印记。我们提出了球粒陨石⁴⁰ K- ⁴⁰ Ar 系统年龄的数据库，并使用小行星尺度热代码与马尔可夫链蒙特卡罗反演相结合对其进行了评估。模拟需要轰击来重现观察到的年龄分布，并识别太阳形成后（50%可信区间）。我们的研究结果将太阳系中巨大行星的不稳定性与气态原行星盘的耗散联系起来。