The paper reviews properties of comets, from historical sightings and interpretations, to contemporary ground- and space-based knowledge. The importance of comets in understanding the present Solar System and its dynamical, physical and chemical evolution, their relationship with other minor bodies, their possible role for the very early phases of our Earth, will be examined. Emphasis will be on the results of the recently completed European Rosetta mission to comet 67P/Churyumov-Gerasimenko, in particular those by OSIRIS, its imaging system. It is fair to say that Rosetta’s results represent a most important step in the development of cometary science, whose full implications start just to surface and will be fully appreciated over several more years.

中文翻译：

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彗星

本文回顾了彗星的属性，从历史的目击和解释到当代的地面和空基知识。我们将研究彗星在了解当前太阳系及其动力学，物理和化学演化，它们与其他小天体之间的关系以及它们在地球早期阶段可能扮演的角色中的重要性。重点将放在最近完成的欧洲罗塞塔号彗星67P / Churyumov-Gerasimenko彗星任务的结果上，特别是OSIRIS成像系统的任务。可以说，罗塞塔的研究成果代表了彗星科学发展中最重要的一步，其全部影响才刚刚浮出水面，并将在未来几年内得到充分的赞赏。