Snapshots of the 73_1 Sim simulation showing eccentricity versus the semimajor axis of the planetary bodies. Panel A shows simulation at ~8.6 Myr of evolution, and each subsequent panel displays the simulation a few thousand years later (B–F). Snapshot A presents a resonant chain of planets located very close to the star, which gets disrupted by another planet that gets too close and excites the group (B). This dynamical instability results in a ~1 M_⊕ planet at first (C), and later on a ~3 M_⊕ planet (F) falling onto the central star.