Characterisation of the main belt asteroid (223) Rosa

C Avdellidou,M Delbo,M Pajola,L Agostini,G Cremonese,E Dotto,G Van Belle,P Palumbo,S Ieva,E Mazzotta Epifani,J Bourdelle De Micas,A Lucchetti,M Devogèle,S Fornasier,N Bruot

doi:10.1051/0004-6361/202142600

Abstract

Context. The ESA JUICE space mission, on its way to study Jupiter’s environment and icy moons, will pass twice through the main asteroid belt. For this reason, the possibility to perform an asteroid flyby has been investigated. Aims. We aim to gain insight into the physical properties of the outer main belt asteroid (223) Rosa, which has been proposed as a potential JUICE flyby target. Methods. We report new visible and near-infrared spectroscopic observations at different rotation phases. Additionally, we perform a literature review of all the available physical properties, such as diameter, albedo, mass, and rotational period. Results. We find that asteroid Rosa is an X-type asteroid that shows no significant spectral variability combining the new and literature spectroscopic data. Its large size and orbital semimajor axis in the outer main belt indicate that Rosa does not belong to the Themis family, while its albedo is only marginally compatible with the family. Rosa’s estimated density is in agreement with those of other low-albedo X-type asteroids. Hence, we propose that Rosa is a planetesimal that accreted in the protoplanetary disk beyond the snow line.

Highlights

The JUpiter ICy moons Explorer (JUICE) is the first large-class mission of the European Space Agency (ESA) Cosmic Vision 2015–2025 programme; it will investigate Jupiter’s atmosphere, magnetosphere, and system of rings
We aim to gain insight into the physical properties of the outer main belt asteroid (223) Rosa, which has been proposed as a potential JUICE flyby target
After retrieving the Spice Kernel Dataset of the JUICE mission1 and the SPK for all size-known asteroids (∼140 000)2, this software determines the minimum distance between the orbit of each asteroid and the JUICE spacecraft

Summary

Introduction

The JUpiter ICy moons Explorer (JUICE) is the first large-class mission of the European Space Agency (ESA) Cosmic Vision 2015–2025 programme; it will investigate Jupiter’s atmosphere, magnetosphere, and system of rings. During the approximately nine-year cruise phase (see Fig. 1), the spacecraft will perform four Earth flybys and one Venus flyby, and will cross the main asteroid belt twice. The latter is a unique opportunity to fly by and investigate at close range one or more asteroids, maximising the scientific return of the full mission as previously demonstrated by the Rosetta closest approach of asteroids (2867) Steins (Keller et al 2010), and (21) Lutetia (Sierks et al 2011).

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Conclusion