In expansion of our recent proposal (Physics, 2020, 2, 213-276) that the solar systems evolution occurred in two stages -- during the first stage, the gaseous giants formed (via disk instability), and, during the second stage (caused by an encounter with a particular stellar-object leading to in-system fission-driven nucleogenesis), the terrestrial planets formed (via accretion) -- we emphasize here that the mechanism of formation of such stellar-objects is generally universal and therefore encounters of such objects with stellar-systems may have occurred elsewhere across galaxies. If so, their aftereffects may perhaps be observed as puzzling features in the spectra of individual stars (such as idiosyncratic chemical enrichments) and/or in the structures of exoplanetary systems (such as unusually high planet densities or short orbital periods). This paper reviews and reinterprets astronomical data within the fission-events framework. Classification of stellar systems as pristine or impacted is offered.