The Distribution of Earth-Impacting Interstellar Objects
Michigan State University（密歇根州立大学）；University of Belgrade（贝尔格莱德大学）；Universitat d'Alacant（阿利坎特大学）；Politecnico di Milano（米兰理工大学）
Darryl Z. Seligman, Dušan Marčeta, Eloy Peña-Asensio
备注：
16 pages, 11 figures, accepted for publication in ApJ. Data availability statement updated, impactor populations available here: https://doi.org/10.5281/zenodo.17693389
In this paper we calculate the expected orbital elements, radiants, and velocities of Earth-impacting interstellar objects. We generate a synthetic population of $\sim10^{10}$ interstellar objects with M-star kinematics in order to obtain $\sim10^4$ Earth-impactors. The relative flux of impactors arriving from the direction of the solar apex and the galactic plane is enhanced by a factor of $\sim2$ relative to the mean. The fastest impactors also arrive from these directions, although Earth-impactors are generally slower than objects in the overall population. This is because the Earth-impacting subset contains a higher fraction of low-eccentricity hyperbolic objects which are more strongly affected by gravitational focusing. Earth-impacting interstellar objects are more likely to have retrograde orbits close to the ecliptic plane. A selection effect makes the distribution of inclination of Earth-impacting interstellar objects uniform/sinusoidal at low/high perihelion distances. In turn, low perihelion impactors have higher impact probability towards the ecliptic plane. The overall impactor population therefore exhibits an intermediate inclination distribution between uniform and sinusoidal. The highest velocity impacts are most likely to occur in the spring when the Earth is moving towards the solar apex. However, impacts in general are more likely to occur during the winter when the Earth is located in the direction of the antapex. Interstellar objects are more likely to impact the Earth at low latitudes close to the equator, with a slight preference for the Northern hemisphere due to the location of the apex. These distributions are independent of the assumed interstellar object number density, albedos, and size-frequency distribution and are publicly available.
A Near-Earth Object Model Calibrated to Earth Impactors
Curtin University（科廷大学）；International Centre for Radio Astronomy Research, Curtin University（科廷大学国际射电天文学研究中心）；Space Science and Technology Centre, Curtin University（科廷大学空间科学与技术中心）；Southwest Research Institute（西南研究所）；NASA Astromaterials Research and Exploration Science Division, Johnson Space Center（美国国家航空航天局约翰逊航天中心天体材料研究与探索科学部）；SETI Institute（搜寻地外文明研究所）；Astronomical Society of Victoria（维多利亚天文学会）；University of Sharjah（沙迦大学）；Sharjah Academy for Astronomy, Space Sciences and Technology（沙迦天文学、空间科学与技术学院）；Faculty of Sciences Semlalia（塞姆拉利亚理学院）
Tracking the Activity of the Interstellar Object 3I/ATLAS through its Perihelion
Southwest Research Institute（西南研究院）；School Observatory Friedrich-Schiller-Gymnasium（弗里德里希-席勒中学天文台）；Jet Propulsion Laboratory（喷气推进实验室）；Institute for Interstellar Studies (i4is US)（星际研究学院）；SnT, University of Luxembourg（卢森堡大学科学与技术学院）；French-Chilean Laboratory for Astronomy（法智天文学联合实验室）
Numerical studies on the link between radioisotopic signatures on Earth and the formation of the Local Bubble. II. Advanced modeling of interstellar 26Al, 53Mn, 60Fe, and 244Pu influxes as traces of past supernovae in the solar neighborhood
Orbital characterization of superbolides observed from space: dynamical association with near-Earth objects, meteoroid streams and identification of hyperbolic meteoroids
Modelling the Dynamics of Potentially Dangerous Large-Earth Impactors
近地天体构成的碰撞威胁越来越多地得到美国国家航空航天局（美国航天局）和欧洲航天局（欧空局）天空调查的证实。目前正在努力开发工具，对未来可能发生的撞击事件进行建模、分析和预测。这项研究的目的是设计一个大型地球撞击事件模型，描述足以对地球造成损害的撞击物进入大气层、地面撞击和撞击后的动态。我们目前的结果，大地球撞击（LEI）事件涉及到一些物体的密度范围之间的$1000 - 8000 kg m^{-3}$。我们使用Python代码来求解微分方程，并在碰撞模拟算法中内置的分析模型上执行计算，同时根据物体速度和直径提供相关的物理输入。我们发现，密度较大的撞击物在撞击大气层时，动量的下降速度较慢。撞击物密度越大，对大气破坏的抵抗力越强，在形成弹坑、产生热辐射、地震效应、喷出物位移和空气爆炸效应方面，地面撞击事件的能量就越大。我们的结论是，与质量较小的物体相比，质量较大的撞击物体保持更大的动能，从而对地球构成更大的碰撞威胁。
