A contact binary satellite of the asteroid (152830) Dinkinesh

• 成果类型: Article
• 署名作者: Levison, Harold F.; Marchi, Simone; Noll, Keith S.; Spencer, John R.; Statler, Thomas S.; Bell, James F.; Bierhaus, Edward B.; Binzel, Richard; Bottke, William F.; Britt, Daniel; Brown, Michael E.; Buie, Marc W.; Christensen, Philip R.; Dello Russo, Neil; Emery, Joshua P.; Grundy, William M.; Hahn, Matthias; Hamilton, Victoria E.; Howett, Carly; Kaplan, Hannah; Kretke, Katherine; Lauer, Tod R.; Manzoni, Claudia; Marschall, Raphael; Martin, Audrey C.; May, Brian H.; Mottola, Stefano; Olkin, Catherine B.; Paetzold, Martin; Parker, Joel Wm.; Porter, Simon; Preusker, Frank; Protopapa, Silvia; Reuter, Dennis C.; Robbins, Stuart J.; Salmon, Julien; Simon, Amy A.; Stern, S. Alan; Sunshine, Jessica M.; Wong, Ian; Weaver, Harold A.; Adam, Coralie; Ancheta, Shanti; Andrews, John; Anwar, Saadat; Barnouin, Olivier S.; Beasley, Matthew; Berry, Kevin E.; Birath, Emma; Bolin, Bryce; Booco, Mark; Burns, Rich; Campbell, Pam; Carpenter, Russell; Crombie, Katherine; Effertz, Mark; Eifert, Emily; Ellis, Caroline; Faiks, Preston; Fischetti, Joel; Fleming, Paul; Francis, Kristen; Franco, Ray; Freund, Sandy; Gallagher, Claire; Geeraert, Jeroen; Gobat, Caden; Gorgas, Donovan; Granat, Chris; Gray, Sheila; Haas, Patrick; Harch, Ann; Hegedus, Katie; Isabelle, Chris; Jackson, Bill; Jacob, Taylor; Jennings, Sherry; Kaufmann, David; Keeney, Brian A.; Kennedy, Thomas; Lauffer, Karl; Lessac-Chenen, Erik; Leonard, Rob; Levine, Andrew; Lunsford, Allen; Martin, Tim; Mcadams, Jim; Mehall, Greg; Merkley, Trevor; Miller, Graham; Montanaro, Matthew; Montgomery, Anna; Murphy, Graham; Myers, Maxwell; Nelson, Derek S.; Ocampo, Adriana; Olds, Ryan; Pelgrift, John Y.; Perkins, Trevor; Pineau, Jon; Poland, Devin; Ramanan, Vaishnavi; Rose, Debi; Sahr, Eric; Short, Owen; Solanki, Ishita; Stanbridge, Dale; Sutter, Brian; Talpas, Zachary; Taylor, Howard; Treiu, Bo; Vermeer, Nate; Vincent, Michael; Wallace, Mike; Weigle, Gerald; Wibben, Daniel R.; Wiens, Zach; Wilson, John P.; Zhao, Yifan
• 署名单位: Southwest Research Institute; National Aeronautics & Space Administration (NASA); NASA Goddard Space Flight Center; National Aeronautics & Space Administration (NASA); Mary W. Jackson NASA Headquarters; Arizona State University; Arizona State University-Tempe; Massachusetts Institute of Technology (MIT); State University System of Florida; University of Central Florida; California Institute of Technology; Johns Hopkins University; Johns Hopkins University Applied Physics Laboratory; Northern Arizona University; University of Cologne; University of Oxford; Universite Cote d'Azur; Observatoire de la Cote d'Azur; Centre National de la Recherche Scientifique (CNRS); Helmholtz Association; German Aerospace Centre (DLR); University System of Maryland; University of Maryland College Park; American University; Cornell University; Rochester Institute of Technology
• 刊物名称: Nature
• ISSN/ISSBN: 0028-4159
• DOI: 10.1038/s41586-024-07378-0
• 发表日期: 2024-05-30
• 关键词: POPULATION; DYNAMICS

摘要

Asteroids with diameters less than about 5 km have complex histories because they are small enough for radiative torques (that is, YORP, short for the Yarkovsky-O'Keefe-Radzievskii-Paddack effect) 1 to be a notable factor in their evolution 2 . (152830) Dinkinesh is a small asteroid orbiting the Sun near the inner edge of the main asteroid belt with a heliocentric semimajor axis of 2.19 au; its S-type spectrum 3,4 is typical of bodies in this part of the main belt 5 . Here we report observations by the Lucy spacecraft 6,7 as it passed within 431 km of Dinkinesh. Lucy revealed Dinkinesh, which has an effective diameter of only 720 m, to be unexpectedly complex. Of particular note is the presence of a prominent longitudinal trough overlain by a substantial equatorial ridge and the discovery of the first confirmed contact binary satellite, now named (152830) Dinkinesh I Selam. Selam consists of two near-equal-sized lobes with diameters of 210 m and 230 m. It orbits Dinkinesh at a distance of 3.1 km with an orbital period of about 52.7 h and is tidally locked. The dynamical state, angular momentum and geomorphologic observations of the system lead us to infer that the ridge and trough of Dinkinesh are probably the result of mass failure resulting from spin-up by YORP followed by the partial reaccretion of the shed material. Selam probably accreted from material shed by this event. Observations from the Lucy spacecraft of the small main-belt asteroid (152830) Dinkinesh reveals unexpected complexity, with a longitudinal trough and equatorial ridge, as well as the discovery of the first contact binary satellite.