The Lucy flyby of (52246) Donaldjohanson: A bilobed asteroid with tumbling rotation
The main belt asteroid (52246) Donaldjohanson (DJ) is a likely member of the Erigone asteroid family. This implies that DJ is a fragment of a larger parent body that was destroyed in a collision about 155 million years ago. We report observations taken during a flyby of DJ by the Lucy spacecraft. We found that DJ is composed of two heavily cratered lobes, connected by a smoother neck, with overall dimensions 8.8 kilometers (km) by 4.4 km by 3.1 km. The crater density is consistent with the Erigone family’s age, except for craters <0.4 km, which have been preferentially erased. DJ rotates slowly in a tumbling state, likely owing to spin-down by radiative forces. Surface spectra show iron-bearing phyllosilicates, indicating moderate aqueous evolution on the parent body.
Authors
- Matthew Montanaro (ORCID: https://orcid.org/0000-0001-7616-3664)
- Amy A. Simon (ORCID: https://orcid.org/0000-0003-4641-6186)
- Masatoshi Hirabayashi (ORCID: https://orcid.org/0000-0002-1821-5689)
- Joshua P. Emery (ORCID: https://orcid.org/0000-0001-9265-9475)
- Rich Burns
- E. S. Costello (ORCID: https://orcid.org/0000-0001-7939-9867)
- W. M. Grundy (ORCID: https://orcid.org/0000-0002-8296-6540)
- J. F. Bell (ORCID: https://orcid.org/0000-0002-2006-4074)
- W. F. Bottke (ORCID: https://orcid.org/0000-0002-1804-7814)
- Thomas S. Statler (ORCID: https://orcid.org/0000-0003-4909-9542)
- H. H. Kaplan (ORCID: https://orcid.org/0000-0002-6562-9462)
- Julien Salmon (ORCID: https://orcid.org/0000-0002-5977-3724)
- C. B. Olkin (ORCID: https://orcid.org/0000-0002-5846-716X)
- O. S. Barnouin (ORCID: https://orcid.org/0000-0002-3578-7750)
- Keith Noll (ORCID: https://orcid.org/0000-0002-6013-9384)
- H. A. Weaver (ORCID: https://orcid.org/0000-0003-0951-7762)
- David Vokrouhlický (ORCID: https://orcid.org/0000-0002-6034-5452)
- S. Mottola (ORCID: https://orcid.org/0000-0002-0457-3872)
- M. Pätzold (ORCID: https://orcid.org/0000-0003-3479-856X)
- Michael E. Brown (ORCID: https://orcid.org/0000-0002-8255-0545)
- Michael A. Vincent (ORCID: https://orcid.org/0000-0002-0338-0534)
- D. Poland
- P. R. Christensen (ORCID: https://orcid.org/0000-0001-9625-4723)
- Sheila Gray
- Fiona Nichols‐Fleming (ORCID: https://orcid.org/0000-0002-7700-5139)
- J. Geeraert (ORCID: https://orcid.org/0000-0001-5377-4745)
- Carly Howett (ORCID: https://orcid.org/0000-0003-1869-4947)
- J. M. Sunshine (ORCID: https://orcid.org/0000-0002-9413-8785)
- A. Verbiscer (ORCID: https://orcid.org/0000-0002-3323-9304)
- J. W. Parker (ORCID: https://orcid.org/0000-0002-3672-0603)
- S. A. Stern (ORCID: https://orcid.org/0000-0001-5018-7537)
- Neil Dello Russo (ORCID: https://orcid.org/0000-0002-8379-7304)
- Frank Preusker (ORCID: https://orcid.org/0000-0001-9005-4202)
- Tod R. Lauer (ORCID: https://orcid.org/0000-0003-3234-7247)
- Russell Carpenter (ORCID: https://orcid.org/0000-0002-8456-3390)
- Richard P. Binzel (ORCID: https://orcid.org/0000-0002-9995-7341)
- Harrison Agrusa (ORCID: https://orcid.org/0000-0002-3544-298X)
- M. W. Buie (ORCID: https://orcid.org/0000-0003-0854-745X)
- Brian A. Keeney (ORCID: https://orcid.org/0000-0003-0797-5313)
- E. B. Bierhaus (ORCID: https://orcid.org/0000-0001-5890-9821)
- Eric Sahr (ORCID: https://orcid.org/0000-0003-4615-8340)
- Silvia Protopapa (ORCID: https://orcid.org/0000-0001-8541-8550)
- S. Marchi (ORCID: https://orcid.org/0000-0003-2548-3291)
- Brian H. May (ORCID: https://orcid.org/0000-0002-5864-3020)
- J. R. Spencer (ORCID: https://orcid.org/0000-0003-4452-8109)
- V. E. Hamilton (ORCID: https://orcid.org/0000-0001-8675-2083)
- Coralie D. Adam (ORCID: https://orcid.org/0000-0002-5795-2446)
- Dennis C. Reuter (ORCID: https://orcid.org/0000-0002-6829-5680)
- J. E. C. Scully (ORCID: https://orcid.org/0000-0001-7139-8050)
- Harold F. Levison (ORCID: https://orcid.org/0000-0001-5847-8099)
- Ishita Solanki
- S. J. Robbins (ORCID: https://orcid.org/0000-0002-8585-2549)
- Mark Effertz
- Katie Hegedus
- Kevin Berry
- Kristen Francis
- Daniel Britt
- David Kaufmann (ORCID: https://orcid.org/0009-0003-1610-1471)
- Thomas Kennedy
- John Andrews
- Jim McAdams
- Emma Birath (ORCID: https://orcid.org/0009-0009-5556-2709)
- Katherine Kretke
- Brian Sutter
- Dale Stanbridge (ORCID: https://orcid.org/0009-0006-0395-5146)
- Jon Pineau (ORCID: https://orcid.org/0009-0005-8763-4042)
Institutions
- University of Central Florida (US)
- University of Hawaiʻi at Mānoa (US)
- California Institute of Technology (US)
- Lockheed Martin (United States) (US)
- Southwest Research Institute (US)
- Planetary Science Institute (US)
- Goddard Space Flight Center (US)
- Georgia Institute of Technology (US)
- Jet Propulsion Laboratory (US)
- Rochester Institute of Technology (US)
- Northern Arizona University (US)
- Charles University (CZ)
- Lowell Observatory (US)
- Centre National d'Études Spatiales (FR)
- Czech Academy of Sciences, Astronomical Institute (CZ)
- Johns Hopkins University Applied Physics Laboratory (US)
- Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR) (DE)
- University of Oxford (GB)
- Planetary Systems (United States) (US)
- Rhenish Institute for Environmental Research (DE)
- Institute of Flight (US)
- Stellar Solutions (United States) (US)
- Observatoire de la Côte d’Azur (FR)
- National Air and Space Museum (US)
- NSF NOIRLab (US)
- BH Consulting (Ireland) (IE)
- American Institute of Aeronautics and Astronautics (US)
- University of Virginia (US)
- Arizona State University (US)
- Massachusetts Institute of Technology (US)
- University of Maryland, College Park (US)
Publication Details
- Journal
- Science
- Published
- 2026-06-18
- DOI
- https://doi.org/10.1126/science.aec0503
- Primary Topic
- Astro and Planetary Science
- Type
- article
- Field-Weighted Citation Impact
- 0.00