The Properties and Origins of Kuiper Belt Object Arrokoth's Large Mounds

TL;DR

This study examines the large mounds on Kuiper Belt Object Arrokoth, analyzing their properties and suggesting they are the original building blocks of the object, posing new questions for solar system formation models.

Contribution

It provides detailed measurements and comparisons of Arrokoth's mounds, proposing they are the primordial building blocks and highlighting their remarkable similarity in size and shape.

Findings

Mounds are broadly self-similar in shape, size, and reflectance.

They are likely the original building blocks of Arrokoth.

The similarity in size challenges existing solar system formation models.

Abstract

We report on a study of the mounds that dominate the appearance of Kuiper Belt Object (KBO) (486958) Arrokoth's larger lobe, named Wenu. We compare the geological context of these mounds, measure and intercompare their shapes, sizes/orientations, reflectance, and colors. We find the mounds are broadly self-similar in many respects and interpret them as the original building blocks of Arrokoth. It remains unclear why these building blocks are so similar in size, and this represents a new constrain and challenge for solar system formation models. We then discuss the interpretation of this interpretation.