Free Astronomy Magazine May-June 2023

13 ASTRO PUBLISHING found a significant magnetic low of about 100 nT, a feature typical for small impact craters.” From a mineralogical point of view, the most interesting results con- cerned the discovery of more than a hundred iron oxide spherules and im- pact breccia. The former are gener- ated by the ablation of the mass of meteorites falling into the atmos- phere and even at the same time as the impact; they typically have an av- erage size of about 200 microns; in the case of Le Clot, their diameters range from a few tens of microns to 1.2 millimeters. Breccia is a type of sedimentary rock, made up of angu- lar fragments of various lithotypes, cemented in a very fine matrix. Like iron oxide spherules, breccia is also a typical (although not exclusive) ele- ment of impact craters. These findings, together with other significant evidence collected during the inspection of Le Clot, undoubt- edly strengthen the meteorite hy- pothesis, although the absence of a significantly raised rim as compared to the surrounding ground lacks a convincing explanation. ! Johan Snijckers