The geology and geophysics of Kuiper Belt object (486958) Arrokoth

J. Spencer (1) , S. Stern , J. Moore , H. Weaver , K. N Singer (1) , C. Olkin , A. Verbiscer , W. Mckinnon , J. Wm. Parker (1) , R. Beyer , J. Keane , T. Lauer , S. Porter , O. White , B. Buratti (2) , M. El-Maarry , C. Lisse , A. Parker , H. Throop , S. Robbins , O. Umurhan , R. P Binzel (3) , D. Britt , M. Buie , A. Cheng , D. Cruikshank , H. Elliott (4) , G. Gladstone (4) , W. Grundy (5) , M. Hill , M. Horányi (6) , D. Jennings (7) , J. Kavelaars (8) , I. Linscott , D. Mccomas (9) , R. Mcnutt , S. Protopapa (1) , D. Reuter (7) , P. Schenk , M. Showalter , L. Young , A. M Zangari (1) , A. Abedin , C. Beddingfield , S. Benecchi , E. Bernardoni , C. Bierson , D. Borncamp , V. Bray , A. Chaikin , R. Dhingra , C. Fuentes , T. Fuse , P. Gay , S. Gwyn (8) , D. Hamilton , J. Hofgartner , M. Holman , A. Howard , C. Howett (1) , H. Karoji , D. Kaufmann , M. Kinczyk , B. May , M. Mountain , M. Pätzold (10) , J.-M. Petit (11) , M. R. Piquette (6) , I. Reid , H. Reitsema , K. Runyon , S. Sheppard , J. Stansberry (12) , T. Stryk , P. Tanga (13) , D. Tholen , D. Trilling (14) , L. Wasserman

1 SwRI - Southwest Research Institute [Boulder]
2 JPL - Jet Propulsion Laboratory
3 MIT - Massachusetts Institute of Technology
4 SwRI - Southwest Research Institute [San Antonio]
5 Lowell Observatory [Flagstaff]
6 LASP - Laboratory for Atmospheric and Space Physics [Boulder]
7 GSFC - NASA Goddard Space Flight Center
8 NRC Herzberg Institute of Astrophysics
9 Princeton University
10 RIU - Rhenish Institute for Environmental Research
11 UTINAM - Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213)
12 LPL - Lunar and Planetary Laboratory [Tucson]
13 LAGRANGE - Joseph Louis LAGRANGE
14 Department of Physics and Astronomy [Flagstaff]

The Cold Classical Kuiper Belt, a class of small bodies in undisturbed orbits beyond Neptune, are primitive objects preserving information about Solar System formation. The New Horizons spacecraft flew past one of these objects, the 36 km long contact binary (486958) Arrokoth (2014 MU69), in January 2019. Images from the flyby show that Arrokoth has no detectable rings, and no satellites (larger than 180 meters diameter) within a radius of 8000 km, and has a lightly-cratered smooth surface with complex geological features, unlike those on previously visited Solar System bodies. The density of impact craters indicates the surface dates from the formation of the Solar System. The two lobes of the contact binary have closely aligned poles and equators, constraining their accretion mechanism.

Domaines: Planétologie et astrophysique de la terre [astro-ph.EP]

J. Spencer, S. Stern, J. Moore, H. Weaver, K. N Singer, et al.. The geology and geophysics of Kuiper Belt object (486958) Arrokoth. Science, 2020, 367 (6481), pp.eaay3999. ⟨10.1126/science.aay3999⟩. ⟨hal-02884319⟩