Horst Uwe Keller教授邀请报告

Abstract:

Their activity sets comets apart from all other planetary bodies.They often produce grandiose appearance on the sky when heated by the sun. Ground-braking interpretations in the middle of the last century characterized the tiny kilometer-sized cometary nuclei well enough to enable targeting the first European (ESA) space mission Giotto at comet Halley in1986. The nature of cometary nuclei - well preserved relicts from the times of planetary formation - changed from “dirty snowball" to “icy dirtball" . This change of paradigm was only slowly accepted but well confirmed by Deep Space, the next flyby mission 15 years after Giotto.The dominance of refractory material makes it difficult to understand the physical processes that drive cometary activity. Over the following 20 years several NASA flyby missions investigated cometary nuclei further while Europe pushed its cornerstone mission Rosetta to rendezvous a comet.The two years long intensive observations of comet 67P from the onset of its activity to its maximum around perihelion and beyond revealed unprecedented details of the nucleus but did not yet solve the conundrum of its activity.

报告人简介：

Dr.Horst UweKeller  is a distinguished scientist in the field of astrophysics and planetary research. His contributions to space missions are profound, having served as Principal Investigator for the Halley Multicolour Camera, the first CCD camera that human ever flew in a deep space science mission, on ESA's Giotto mission,the SIR Infrared Spectrometer for ESA's SMART 1 lunar mission, and the OSIRIS Science lmagers on ESA's Rosetta comet mission, among others. Dr. Keller's work has earned himnumerous accolades, including the Stern Gerlach Prize, the Christiaan Huygens Medal, and the honoris causa Aix-Marseille Université.  Dr. Keller has authored approximately 300 publications on a variety of topics including the physics of comets, planetary atmospheres, and image analysis methods. He continues to be active in the analysis of data from the instruments he has helped to develop, significantly advancing ou r understanding of the solar system.