Consistency of an outer–Galactic-disk origin with 3I/ATLAS’s present-day trajectory

Determine whether an origin of interstellar comet 3I/ATLAS in the most distant, metal-depleted outer regions of the Milky Way’s Galactic disk is consistent with the comet’s present-day Galactic trajectory inferred from its inbound velocity vector and kinematic constraints.

Background

In the Discussion, the authors note that extrapolating observed Galactic 12C/13C gradients could allow values approaching those measured for 3I/ATLAS in the far outer disk, making an outer–Galactic-disk origin a conceivable scenario. However, they emphasize that any such interpretation must be reconciled with the object’s current kinematics.

They further discuss that while chemical evolution models and radial gradients suggest potential isotopic conditions in the outer disk, confirming this scenario requires establishing that the observed trajectory of 3I/ATLAS can plausibly arise from such an origin within the Milky Way’s dynamical context.