Ryugu\u2019s observed volatile loss did not arise from impact heating alone

Kosuke Kurosawa,Ryota Moriwaki,Hikaru Yabuta,Goro Komatsu,Takafumi Matsui,Ko Ishibashi

doi:10.1038/s43247-021-00218-3

Abstract

Carbonaceous asteroids, including Ryugu and Bennu, which have been explored by the Hayabusa2 and OSIRIS-REx missions, were probably important carriers of volatiles to the inner Solar System. However, Ryugu has experienced significant volatile loss, possibly from hypervelocity impact heating. Here we present impact experiments at speeds comparable to those expected in the main asteroid belt (3.7 km s−1 and 5.8 km s−1) and with analogue target materials. We find that loss of volatiles from the target material due to impacts is not sufficient to account for the observed volatile depletion of Ryugu. We propose that mutual collisions in the main asteroid belt are unlikely to be solely responsible for the loss of volatiles from Ryugu or its parent body. Instead, we suggest that additional processes, for example associated with the diversity in mechanisms and timing of their formation, are necessary to account for the variable volatile contents of carbonaceous asteroids.

Highlights

Carbonaceous asteroids, including Ryugu and Bennu, which have been explored by the Hayabusa[2] and OSIRIS-REx missions, were probably important carriers of volatiles to the inner Solar System
Previous impact experiments using metal plates flying at
This is the reason why impact heating has been considered as the cause of the diversity in the volatile contents of carbonaceous meteorites and those observed in the two asteroids

Summary

Introduction

Carbonaceous asteroids, including Ryugu and Bennu, which have been explored by the Hayabusa[2] and OSIRIS-REx missions, were probably important carriers of volatiles to the inner Solar System. Previous impact experiments using metal plates flying at

Methods

Results

Conclusion