The Color of 2014 MU69
Abstract
On January 1, 2019 NASA's New Horizons spacecraft flew close to the Kuiper Belt Object (486958) 2014 MU69 nicknamed "Ultima Thule" (herein MU69). MU69 is a bi-lobed contact binary with an unusual flattened shape. Based on its orbit, MU69 is considered a member of the Cold Classical Kuiper Belt population. This class of objects is thought to be more or less dynamically undisturbed bodies that formed in situ ~4.5 Gyr ago and have since remained at or close to their current, large heliocentric distances. Since MU69 appears to be well preserved, New Horizons' observations of it serve as an opportunity to better understand planetesimal accretion and the earliest stages of planetary formation. In this talk we will focus on the color of MU69's surface, its context as a member of the Kuiper Belt, and the implications its color has for formation scenarios. New Horizons found MU69 to be very red in color (which is consistent with pre-encounter Hubble Telescope observations). Both lobes show basically the same average color. However, subtle color variations exist across the body, for example the less red, higher albedo patches near the "neck" region where the lobes come together. We will explore how these variations correlate with the surface geology of MU69 as well as the insolation and "climate zone" boundaries. We will also consider MU69's color in the broader context of the Kuiper Belt. This red color is consistent with the rest of the Cold Classical Kuiper Belt population, which it is dynamically a member of. Finally, we will discuss the implications MU69's color has for constraining and better understanding its possible formation scenarios.
- Publication:
-
American Astronomical Society Meeting Abstracts #235
- Pub Date:
- January 2020
- Bibcode:
- 2020AAS...23541903E