One of the key goals of the Rosetta mission was to understand how, where and when comets formed in our solar system. There are two major hypotheses for the origin of comets, both pre-Rosetta: (1) hierarchical accretion of dust and ice grains in the Solar Nebula and (2) the growth of pebbles, which are then brought together by streaming instabilities in the Solar Nebula to form larger bodies. Rosetta provided a wealth of new information on comet nuclei and confirmed many past ideas on comets, e.g., high volatile content, lack of aqueous alteration of grains, and the low bulk density of the nucleus. Rosetta also provided new data on the nature of cometary activity, the active geology on the nucleus surface and the interior structure and bulk density of the nucleus. Supporters of the above-mentioned origin hypotheses each find confirmation of their ideas in the Rosetta results. But the question of which hypothesis is preferred, or if there are other, better hypotheses that could be invoked, could not be answered. Theoretical studies suggest that comet nuclei were collisionally processed in the Primordial Disk though it is not clear that the nuclei we see today display the effects of that process. Both theoretical and observational studies suggest that the major end-states for cometary nuclei are dynamical ejection, random disruption and disintegration, and/or evolution of nuclei to inactive, asteroidal-appearing objects. Rosetta has provided us with many new insights that will help to guide future cometary missions, observations, experiments and theoretical investigations that will lead to answers to the fundamental questions with regard to cometary origin.

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彗核的起源与演化

罗塞塔任务的主要目标之一是了解彗星在我们的太阳系中是如何、在何处以及何时形成的。彗星起源有两个主要假设，都是罗塞塔之前的：(1) 太阳星云中尘埃和冰粒的分级吸积；(2) 鹅卵石的生长，然后由太阳中的流动不稳定性聚集在一起星云形成更大的天体。Rosetta 提供了大量关于彗核的新信息，并证实了许多过去关于彗星的想法，例如高挥发物含量、缺乏颗粒的水蚀变以及彗核的低堆积密度。罗塞塔还提供了有关彗星活动性质、原子核表面活动地质以及原子核内部结构和体积密度的新数据。上述起源假说的支持者都在 Rosetta 结果中找到了他们想法的证实。但是，关于哪种假设更受欢迎，或者是否有其他更好的假设可以被引用的问题无法回答。理论研究表明，彗核在原始盘中受到了碰撞处理，尽管我们今天看到的彗核是否显示出该过程的影响尚不清楚。理论和观察研究都表明，彗星核的主要终结状态是动力喷射、随机破坏和解体，和/或核演化为不活跃的、出现小行星的物体。Rosetta 为我们提供了许多新的见解，这些见解将有助于指导未来的彗星任务、观测、