Successful Kinetic Impact into an Asteroid for Planetary Defense
R. Terik Daly, Carolyn M. Ernst, Olivier S. Barnouin, Nancy L. Chabot, Andrew S. Rivkin, Andrew F. Cheng, Elena Y. Adams, Harrison F. Agrusa, Elisabeth D. Abel,… 展开作者
R. Terik Daly, Carolyn M. Ernst, Olivier S. Barnouin, Nancy L. Chabot, Andrew S. Rivkin, Andrew F. Cheng, Elena Y. Adams, Harrison F. Agrusa, Elisabeth D. Abel, Amy L. Alford, Erik I. Asphaug, Justin A. Atchison, Andrew R. Badger, Paul Baki, Ronald-L. Ballouz, Dmitriy L. Bekker, Julie Bellerose, Shyam Bhaskaran, Bonnie J. Buratti, Saverio Cambioni, Michelle H. Chen, Steven R. Chesley, George Chiu, Gareth S. Collins, Matthew W. Cox, Mallory E. DeCoster, Peter S. Ericksen, Raymond C. Espiritu, Alan S. Faber, Tony L. Farnham, Fabio Ferrari, Zachary J. Fletcher, Robert W. Gaskell, Dawn M. Graninger, Musad A. Haque, Patricia A. Harrington-Duff, Sarah Hefter, Isabel Herreros, Masatoshi Hirabayashi, Philip M. Huang, Syau-Yun W. Hsieh, Seth A. Jacobson, Stephen N. Jenkins, Mark A. Jensenius, Jeremy W. John, Martin Jutzi, Tomas Kohout, Timothy O. Krueger, Frank E. Laipert, Norberto R. Lopez, Robert Luther, Alice Lucchetti, Declan M. Mages, Simone Marchi, Anna C. Martin, Maria E. McQuaide, Patrick Michel, Nicholas A. Moskovitz, Ian W. Murphy, Naomi Murdoch, Shantanu P. Naidu, Hari Nair, Michael C. Nolan, Jens Ormö, Maurizio Pajola, Eric E. Palmer, James M. Peachey, Petr Pravec, Sabina D. Raducan, K. T. Ramesh, Joshua R. Ramirez, Edward L. Reynolds, Joshua E. Richman, Colas Q. Robin, Luis M. Rodriguez, Lew M. Roufberg, Brian P. Rush, Carolyn A. Sawyer, Daniel J. Scheeres, Petr Scheirich, Stephen R. Schwartz, Matthew P. Shannon, Brett N. Shapiro, Caitlin E. Shearer, Evan J. Smith, R. Joshua Steele, Jordan K Steckloff, Angela M. Stickle, Jessica M. Sunshine, Emil A. Superfin, Zahi B. Tarzi, Cristina A. Thomas, Justin R. Thomas, Josep M. Trigo-Rodríguez, B. Teresa Tropf, Andrew T. Vaughan, Dianna Velez, C. Dany Waller, Daniel S. Wilson, Kristin A. Wortman, Yun Zhang
While no known asteroid poses a threat to Earth for at least the next century, the catalog of near-Earth asteroids is incomplete for objects whose impacts would produce regional devastation. Several approaches have been proposed to potentially prevent an asteroid impact with Earth by deflecting or disrupting an asteroid. A test of kinetic impact technology was identified as the highest priority space mission related to asteroid mitigation. NASA's Double Asteroid Redirection Test (DART) mission is the first full-scale test of kinetic impact technology. The mission's target asteroid was Dimorphos, the secondary member of the S-type binary near-Earth asteroid (65803) Didymos. This binary asteroid system was chosen to enable ground-based telescopes to quantify the asteroid deflection caused by DART's impact. While past missions have utilized impactors to investigate the properties of small bodies those earlier missions were not intended to deflect their targets and did not achieve measurable deflections. Here we report the DART spacecraft's autonomous kinetic impact into Dimorphos and reconstruct the impact event, including the timeline leading to impact, the location and nature of the DART impact site, and the size and shape of Dimorphos. The successful impact of the DART spacecraft with Dimorphos and the resulting change in Dimorphos's orbit demonstrates that kinetic impactor technology is a viable technique to potentially defend Earth if necessary.
Planetary Chaos and the (In)stability of Hungaria Asteroids
匈牙利小行星群位于主小行星带内部，半长轴在1.8至2天文单位之间，离心率低，倾角为16至35度。最近，有人提出匈牙利小行星的数量正在长期下降，这可能与晚期重轰炸（LHB）撞击物有关（Bottke等人，2012年）。虽然Bottke et al.（2012）和Bottke et al.（2012）重现了呈指数下降的匈牙利人种群，但真正的匈牙利人从未被证实具有相同程度的不稳定性。在这里，我们发现，匈牙利的稳定性是强烈依赖于火星的偏心率，这是混乱和不可预测的陀螺时间尺度上的演变。我们发现，火星的高偏心率主要通过与火星的近距离接触而影响匈牙利人，而不是行星的长期模式。然而，匈牙利目前的最小近日点（在百万年时间尺度上）并不能诊断它们的长期稳定性，这是由于一些长期和平均运动共振影响匈牙利地区（Milani等人，2010年）。我们的结论是，行星的混乱使得它不可能确定观察到的匈牙利的有效寿命。此外，火星离心率的长期变化可能导致匈牙利的损失随着时间的推移而变化。我们推测，一些最稳定的匈牙利可能已经被放置在他们目前的轨道时，火星的偏心率明显高于今天。
Habitable Zones for Earth-mass Planets in Multiple Planetary Systems
本文通过数值模拟研究了多行星系中地球质量行星的宜居带和动力学结构。例如，在HD 69830系统中，我们广泛地探索了三个海王星质量的同伴的行星配置，其中一个大质量的类地行星居住在0.07 AU $\leq a \leq$ 1.20 AU，以研究该系统中的小行星结构。我们强调，有至少$10^5$年的稳定区的低质量类地行星位于0.3和0.5 AU之间，和0.8和1.2 AU的最终偏心率为$e < 0.20$。此外，我们还发现小行星带的积累或耗尽也受到外行星轨道共振的影响，例如，与行星C的2：1和3：2平均运动共振（MMRs）以及与行星D的5：2和1：2 MMRs的小行星间隙。在动力学意义上，潜在类地行星或HZ存在的合适候选区域为0.35 AU $< a < $ 0.50 AU，以及0.80 AU $< a < $ 1.00 AU，这对于该系统中可能存在的小行星结构是有意义的。
Asteroid Disruption and Deflection Simulations for Multi-Modal Planetary Defense
University of California - Santa Barbara（加州大学圣塔芭芭拉分校）；NASA Ames Research Center（美国国家航空航天局艾姆斯研究中心）；University of New Mexico（新墨西哥大学）；New Mexico Institute of Mining and Technology（新墨西哥矿业理工学院）；Johns Hopkins University Applied Physics Laboratory（约翰斯·霍普金斯大学应用物理实验室）；Sandia National Laboratories（桑迪亚国家实验室）
On The Effect of Giant Planets on the Scattering of Parent Bodies of Iron Meteorite from the Terrestrial Planet Region into the Asteroid Belt: A Concept Study
Enabling tomorrow's planetary defence and space resource economy: Autonomous fleet-based asteroid rendezvous missions
University of Liverpool（利物浦大学）；NASA（美国国家航空航天局）；Colorado Center for Astrodynamics, University of Colorado（科罗拉多大学轨道动力学中心）；Institute of Space and Astronautical Science (ISAS), JAXA（宇宙科学研究所 (ISAS)，日本宇宙航空研究开发机构）
NEOWISE Observations Of The Potentially Hazardous Asteroid (99942) Apophis
大型潜在危险小行星（PHAs）在行星碰撞的情况下能够造成全球性灾难。因此，迅速评估此类物体的物理特性对于确定其潜在风险规模至关重要。我们将近地小行星（99942）阿波菲斯视为2020-2021年近距离接近期间新发现的物体，作为模拟行星防御演习的一部分。近地物体广域红外巡天探测器探测到了该物体，并利用热和热物理建模对两个有效波段（3.4 $μ$ m和4.6 $μ$ m）收集的数据进行了分析。我们的研究结果表明，阿波菲斯是一个细长的对象与有效的球形直径D $_{eff}$ = 340 $\pm$ 70米，几何视觉的$_{V}$ = 0.31 $\pm$ 0.09，和热惯性$Γ$ $\sim$ 150 - 2850 Jm $^{-2}$ s $^{-0.5}$ K $^{-1}$与最佳拟合值为550 Jm $^{-2}$ s $^{-0.5}$ K $^{-1}$。NEOWISE“发现”号的观测结果显示，（99942）阿波菲斯是一颗潜在的危险小行星，可能会在区域一级造成损害，而不是全球性的。
Optical and acoustic ground effects simulations from terminal defense asteroid disruption via the PI method
University of California - Santa Barbara（加州大学圣塔芭芭拉分校）；NASA Ames Research Center（美国国家航空航天局艾姆斯研究中心）；University of New Mexico（新墨西哥大学）；New Mexico Institute of Mining and Technology（新墨西哥矿业与技术学院）；Sandia National Laboratories（桑迪亚国家实验室）
Shaking and Tumbling: Short- and Long-Timescale Mechanisms for Resurfacing of Near-Earth Asteroid Surfaces from Planetary Tides and Predictions for the 2029 Earth Encounter by (99942) Apophis
Evaluating Short-Warning Mitigation via Intentional Robust Disruption of a Hypothetical Impact of Asteroid 2023 NT1
University of California, Santa Barbara（加州大学圣塔芭芭拉分校）；New Mexico Institute of Mining and Technology（新墨西哥矿业技术学院）；University of New Mexico（新墨西哥大学）；NASA Ames Research Center（美国宇航局艾姆斯研究中心）；Sandia National Laboratories（桑迪亚国家实验室）；Los Alamos National Laboratory（洛斯阿拉莫斯国家实验室）；University of Utah（犹他大学）
