Examinando por Autor "Soldini, Stefania"

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Acceso Abierto
Ejecta from the DART-produced active asteroid Dimorphos
(Springer Nature, 2023-03-01) Li, Jian Yang; Hirabayashi, Masatoshi; Farnham, Tony; Sunshine, Jessica; Knight, Matthew; Tancredi, Gonzalo; Moreno, Fernando; Murphy, Brian; Opitom, Cyrielle; Chesley, Steve; Scheeres, Daniel; Thomas, Cristina; Fahnestock, Eugene; Cheng, Andrew; Dressel, Linda; Ernst, Carolyn; Ferrari, Fabio; Fitzsimmons, Alan; Leva, Simone; Ivanovski, Stavro; Kareta, Theodore; Kolokolova, Ludmilla; Lister, Tim; Raducan, Sabina; Rivkin, Andrew; Rossi, Alessandro; Soldini, Stefania; Stickle, Angela; Vick, Alison; Vicent, Jean-Baptiste; Weaver, Harold; Bagnulo, Stefano; Bannister, Michele; Cambioni, Saverio; Campo Bagatin, Adriano; Chabot, Nancy; Cremonese, Gabriele; Daly, Terik; Dotto, Elisabetta; Glenar, David; Granvik, Mikael; Hasselmann, Pedro; Herreros, Isabel; Jacobson, Seth; Jutzi, Martín; Kohout, Tomas; La Forgia, Tomas; Lazzarin, Monica; Lin, Zhong Yi; Lolachi, Ramin; Lucchetti, Alice; Makadia, Rahil; Mazzotta Epifani, Elena; Michel, Patrick; Migliorini, Alessandra; Moskovitz, Nicholas; Ormö, Jens; Pajola, Maurizio; Sánchez, Paul; Schwartz, Stephen; Snodgrass, Colin; Steckloff, Jordan; Stubbs, Timothy; Trigo Rodríguez, Josep; Swiss National Science Foundation (SNSF); National Aeronautics and Space Administration (NASA); Agencia Estatal de Investigación (AEI); Agencia Nacional de Investigación e Innovación (ANII); Institute of Geology of the Czech Academy of Sciences; Academy of Finland; Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737
Some active asteroids have been proposed to be formed as a result of impact events. Because active asteroids are generally discovered by chance only after their tails have fully formed, the process of how impact ejecta evolve into a tail has, to our knowledge, not been directly observed. The Double Asteroid Redirection Test (DART) mission of NASA, in addition to having successfully changed the orbital period of Dimorphos, demonstrated the activation process of an asteroid resulting from an impact under precisely known conditions. Here we report the observations of the DART impact ejecta with the Hubble Space Telescope from impact time T + 15 min to T + 18.5 days at spatial resolutions of around 2.1 km per pixel. Our observations reveal the complex evolution of the ejecta, which are first dominated by the gravitational interaction between the Didymos binary system and the ejected dust and subsequently by solar radiation pressure. The lowest-speed ejecta dispersed through a sustained tail that had a consistent morphology with previously observed asteroid tails thought to be produced by an impact. The evolution of the ejecta after the controlled impact experiment of DART thus provides a framework for understanding the fundamental mechanisms that act on asteroids disrupted by a natural impact.
Acceso Abierto
Morphology of ejecta features from the impact on asteroid Dimorphos
(Nature, 2025-02-14) Ferrari, Fabio; Panicucci, Paolo; Merisio, Gianmario; Pugliatti, Mattia; Li, Jian Yang; Fahnestock, Eugene; Raducan, Sabina; Jutzi, Martín; Soldini, Stefania; Hirabayashi, Masatoshi; Merrill, Colby; Michel, Patrick; Moreno, Fernando; Tancredi, Gonzalo; Sunshine, Jessica; Ormö, Jens; Herreros, Isabel; Agrusa, Harrison; Karatekin, Ozgur; Zhang, Yun; Chabot, Nancy; Cheng, Andrew; Richardson, Derek; Rivkin, Andrew; Campo Bagati, Adriano; Farnham, Tony; Ivanovski, Stavro; Lucchetti, Alice; Pajola, Maurizio; Rossi, Alessandro; Scheeres, Daniel; Tusberti, Filippo; National Aeronautics and Space Administration (NASA); European Research Council (ERC); Swiss National Science Foundation (SNSF); Centre National D'Etudes Spatiales (CNES); Agencia Estatal de Investigación (AEI); Agencia Nacional de Investigacíon e Innovacíon (ANII); Consejo Superior de Investigaciones Científicas (CSIC); Agenzia Spaziale Italiana (ASI)
Hypervelocity impacts play a significant role in the evolution of asteroids, causing material to be ejected and partially reaccreted. However, the dynamics and evolution of ejected material in a binary asteroid system have never been observed directly. Observations of Double Asteroid Redirection Test (DART) impact on asteroid Dimorphos have revealed features on a scale of thousands of kilometers, including curved ejecta streams and a tail bifurcation originating from the Didymos system. Here we show that these features result naturally from the dynamical interaction of the ejecta with the binary system and solar radiation pressure. These mechanisms may be used to constrain the orbit of a secondary body, or to investigate the binary nature of an asteroid. Also, they may reveal breakup or fission events in active asteroids, and help determine the asteroid’s properties following an impact event. In the case of DART, our findings suggest that Dimorphos is a very weak, rubble-pile asteroid, with an ejecta mass estimated to be in the range of (1.1-5.5)×107 kg.