Determine whether Nice models reproduce the observed TNO colour distribution

Determine whether Nice-model simulations of Solar System evolution can reproduce the observed trans-Neptunian-object colour distribution after 4.5 Gyr of evolution.

Background

The paper compares the stellar-flyby scenario with Nice-model explanations of the trans-Neptunian-object populations. While the Nice models reproduce several major dynamical populations, their ability to account for the observed colour distribution is not established in the discussion.

The unresolved issue is specifically whether a Nice-model simulation evolved for 4.5 Gyr can match the observed TNO colour distribution, rather than merely reproduce the orbital populations.

References

Currently, it is unclear whether the Nice models also produced the observed TNO colour distribution.

— Trans-Neptunian Object dynamics even better explained by a stellar flyby after 4.5 Gyr of evolution  (2609.03575 - Pfalzner et al., 3 Sep 2026) in Section 6.2, “Comparison to other models”