Explaining the elongated shape of 'Oumuamua by the Eikonal abrasion model

TL;DR

This paper proposes that the elongated shape of 'Oumuamua can be explained by a model where primordial asteroids are shaped by abrasion from tiny particles, using the Eikonal equation to predict such elongation.

Contribution

It introduces a model based on the Eikonal equation showing how abrasion from tiny particles can produce highly elongated asteroid shapes like 'Oumuamua.

Findings

Abrasion by tiny particles leads to elongated asteroid shapes.

The Eikonal model predicts the specific elongation observed in 'Oumuamua.

Supports the idea that shape evolution can be driven by surface abrasion.

Abstract

The photometry of the minor body with extrasolar origin (1I/2017 U1) 'Oumuamua revealed an unprecedented shape: Meech et al. (2017) reported a shape elongation b/a close to 1/10, which calls for theoretical explanation. Here we show that the abrasion of a primordial asteroid by a huge number of tiny particles ultimately leads to such elongated shape. The model (called the Eikonal equation) predicting this outcome was already suggested in Domokos et al. (2009) to play an important role in the evolution of asteroid shapes.