Collaborative Research: Tidal disruption of near-Earth asteroids

这项由西南研究院和马里兰大学帕克分校合作的项目研究了引力如何重塑或撕裂近地小行星。众所周知，“碎石堆”小行星(松散的物质集合)和彗星在靠近行星时，会通过一种称为潮汐扭曲和破坏的过程来重塑或分离。这个研究小组将使用计算机模拟和观测的输入来检查潮汐破坏如何改变近地天体的数量。他们将讨论一些主题，如产生了多少碎片，它们的轨道是什么，以及有多少奇怪的形状可以归因于这个过程。这将为他们的历史和潜在的未来提供重要的洞察，并与行星防御相关。近地小行星是太阳系中距离最近的天体之一，因此也是研究最多的天体之一，但尚不清楚近地小行星对近地小行星的影响有多普遍。这个研究小组将模拟与类地行星有近距离飞行的碎石堆小行星之间的相互作用。他们将确定他们的软球离散代码是否可以产生一些形状不规则的近地天体，重新处理它们的表面，并改变近地小行星的大小和轨道分布。通过对颗粒之间的表面相互作用进行精确建模，该小组将捕捉摩擦力和不规则形状组成部分的影响，形成一整套潮汐破坏模型。对所有可能的类地行星相遇情景(近距离接近和速度)进行测试，包括一系列自旋状态(自旋轴方向和自转速度)和内部结构(大型内部块体)，将被用来创建一份必要的结果目录，以估计这一过程在多大程度上改变了近地人口，并能够估计最有可能受到影响的天体。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This collaborative project between Southwest Research Institute and the University of Maryland College Park studies how gravitational forces can reshape or tear apart near-Earth asteroids (NEAs). “Rubble-pile” asteroids (which are loose collections of material) and comets are known to reshape or come apart, through a process known as tidal distortion and disruption, as they pass close to planets. This research team will use computer simulations with inputs from observations to examine how tidal disruption changes the population of NEAs. They will address topics such as how many fragments are created, what their orbits are, and how many odd shapes can be attributed to the process. This will provide important insight into their history and potential futures and has relevance to planetary defense. The broader impacts leverage the interest of the general public in NEAs to continue a long-running public outreach program and to build an accessible toolset and lesson plan for wide use.Near-Earth asteroids are some of the closest and therefore best-studied objects in the Solar System, yet it is not known how pervasive the effects of tidal disruption could be among NEAs. This research team will model the interaction of rubble-pile asteroids having close flybys of terrestrial planets. They will determine whether their soft-sphere discrete code can produce some of the irregularly shaped NEAs, re-process their surfaces, and alter the size and orbital distribution of near-Earth asteroids. Through accurate modeling of the surface interactions between particles, this group will capture the effect of frictional forces and irregular shaped constituent pieces for a complete suite of tidal disruption models. Testing over the entire range of possible encounter scenarios (close approach and velocity) for the terrestrial planets, including a range of spin states (spin axis orientation and spin rates) and internal structure (large interior blocks), will be used to create a catalog of outcomes necessary to estimate how widely this process has altered the near-Earth population and be able to estimate the bodies most likely to have been affected.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.