Early migration damped Neptune's eccentricity. Here, we assume that the value was much smaller than observed today, and show closest flyby of ∼0.1 M⊙ star over ∼4.5 Gyr in field, at a distance ∼103 au would explain eccentricity today.

In this paper, we present and defend a natural yet novel analysis of normative reasons. According to what call support-explanationism, for fact be reason φ is it explain why there's support φ-ing. We critically consider the two main rival forms explanationism—ought-explanationism, on which reasons facts about ought, good-explanationism, goodness—as well as popular Reasons-First view, takes noti...