Testing the asteroid Pallas as the parent body of the active NEA Phaethon

原行星是迷人的天体，提供了在行星上观察到的地质过程的特殊例子，例如，火山作用，构造和分化，但在一个特殊的设置低于1000公里的机构，没有发展到完整的行星。观测表明，（2）智神星填补了（1）谷神星和（4）灶神星之间的空白。黎明使命探测的原行星谷神星和灶神星具有类似的地质特征，具有相似的表面重力。虽然灶神星由于其无水成分比富含水的谷神星密度大得多，但智神星的密度也更大，但目前还不清楚是由于最初的含水量较小，还是水分流失。帕拉斯提供了一个案例研究，为这类物体提供了一个新的和更完整的理解，这类物体与典型的小行星非常不同，是行星的前身，并经历了行星过程。重要的是，命运+使命将调查的是近地小行星（3200）法厄同的建议母体。以智神星为重点，拟议的项目目标是完成五个科学目标，重点是密度，组成，结构和年表。A.通过模拟孔隙度的演变并推导出计算出的最终体积密度与智星的体积密度之间的匹配，从其体积密度和CM样表面组成推导智星的吸积时间。B。确定哪种内部成分和结构与水合（亚）表面一致，例如，如果水化表面意味着地幔和地壳中的高冰分数，则通过计算温度和孔隙度的演变并推导出材料的强度和成分。C.限制智神星大地测量性质的演变，例如，在A.和B。D.通过比较法厄同的物理特性与帕拉斯的物理特性，确定是否可以从帕拉斯产生具有法厄同物理特性的物体，因为假设法厄同是其母小行星的单个碎片。E.确定智神星的热演化是否与CM、CY或塔吉什湖的热年代记录相一致，即，如果智神星可以是这些陨石群中任何一个的母体，通过拟合这些陨石群的热演化计算数据。该项目旨在缩小谷神星和灶神星之间在我们对原行星的理解方面的差距，调查帕拉斯是否可以成为辉腾的母小行星，并通过建模研究支持命运+太空使命。

Protoplanets are fascinating bodies that provide a special sort of examples of geological processes observed on planets, e.g., volcanism, tectonics, and differentiation, yet in a special setting of sub-1000 km bodies that did not develop to full planets. Observations suggest that (2) Pallas fills a gap between (1) Ceres and (4) Vesta. Protoplanets Ceres and Vesta explored by the Dawn mission have comparable geology given similar surface gravities. While Vesta is much denser due to its anhydrous composition than the water-rich Ceres, Pallas is also denser, but it is unclear if due to an initially smaller water content, or water loss. Pallas offers a case study for a new and much more complete understanding of this class of objects which are very different from typical small asteroids, are precursors of planets, and have undergone planetary processes. Importantly, it is the suggested parent body of the near-Earth asteroid (3200) Phaethon that will be investigated by the Destiny+ mission. Focusing on Pallas, the proposed project targets to complete five science objectives focused on density, composition, structure, and chronology. A. Derive the accretion time of Pallas from its bulk density and a CM-like surface composition by modelling the evolution of the porosity and deriving a match between the calculated final bulk density and that of Pallas. B. Determine which internal composition and structure are consistent with a hydrated (sub-) surface, e.g., if the hydrated surface implies a high ice fraction in the mantle and crust, by calculating the evolution of the temperature and porosity and deriving the strength and composition of the material. C. Constrain the evolution of geodetic properties of Pallas, e.g., MOI coefficient and spin velocity, for the parameters constrained in A. and B. D. Determine if an object with Phaethon´s physical properties can be produced from Pallas for the assumption that Phaethon is a single fragment of its parent asteroid by comparing Phaethon´s physical properties with those obtained for Pallas. E. Determine if the thermal evolution of Pallas is compatible with the thermo-chronological record of CM, CY, or Tagish Lake chondrites, i.e., if Pallas can be the parent body of either of these groups, by fitting the thermal evolution calculated to the data available for these meteorite groups. The project aims to closing the gap between Ceres and Vesta in our understanding of protoplanets, to investigating if Pallas can be the parent asteroid of Phaeton, and to supporting the Destiny+ space mission with modeling studies.