An Unseen Planet in the Solar System

Fri, March 11, 2016

Colloquium image for website

Beyond the orbit of Neptune, lies an expansive field of icy debris, known as the Kuiper belt. For the most part, the collective orbital structure of the Kuiper belt can be understood within the framework the present-day solar system. However, recent analyses have shown that distant orbits that belong to the scattered disk population of the Kuiper belt exhibit an unexpected alignment in physical space. In this talk, I will argue that the observed orbital clustering can be maintained by a distant eccentric ~10 Earth mass planet, whose orbit lies in approximately the same plane as those of the distant Kuiper belt objects, but whose perihelion is anti-aligned with respect to the minor bodies. In addition to accounting for the observed orbital grouping, the existence of such a planet naturally explains the presence of high perihelion Sedna-like objects, as well as the known collection of high semi-major axis objects with inclinations between 60 and 150 degrees whose origin was previously elusive.