SSMP-Excursion to the Ries and Steinheim meteorite impact craters, Germany

摘要

The Ries and Steinheim twin impact craters (24 and 3.8 km diameter) were formed in the Miocene, 14.3 + 0.2 Ma ago (Buchner et al., 2003). These two craters are the best preserved of the very few impact craters in central Europe. Chemical evidence (El Goresy and Chao, 1976) suggests that the impacting meteoroid had a chondritic composition, and its size is considered to be roughly l/20th of the crater diameter. This means that the main meteoroid producing the Ries crater had a diameter of ca. 1 km. This meteoroid possibly had a smaller satellite (,,Moon"), ca. 100-200 m in diameter, which produced the Steinheim impact crater (see for example asteroid 243 Ida and its small satellite).