In the southeastern Wyoming of the United States, scientists have discovered a whole range of small craters ranging in diameter from 10 to 70 meters. Inscribed in sediments of the Permian era (280 million years), this multitude of impact structures was first attributed to the disintegration of a larger one. small star when entering the atmosphere. Actually, no major crater is visible in the landscape of the surrounding area. However, during field investigations, it appeared that the expansion of the sphere of influence could be explained by this hypothesis.

A ballistic study to trace the origin of the crater

Like spies, the scientists conducted a ballistic study on each small crater to trace its origin. Thirty-one impacts thus far have been investigated, but more than 60 other structures may also have been part of the crater region. The distribution of impacts first shows that the craters are not randomly distributed: they form many small clusters, which define a corridor 30-45° Points in a specific direction. Crater also has one morphology specific in the long term. This shape indicates that the crater-producing objects hit the ground at a relatively flat angle. This data thus enabled the researchers to reconstruct the trajectories of the objects. Taken together, these trajectories show a radial pattern: all objects at the origin of the crater region will come from a single source.

major influence brands

All results suggest that the dozens of smaller craters identified in Wyoming would therefore not be associated with the disintegration of one small star in the atmosphere but would result in blocks removed during a major impact. So these are secondary craters, scattered around a main pit, as the crown of ejecta. While this type of formation is very common on Moon Where on Mars For example, it had never been seen on Earth until now.

This absence is primarily to be linked to processes of erosion, particularly dominant on our planet, which To quickly erase traces of meteorite impact, especially the younger ones. tectonic activity and sedimentation As the Earth’s surface is constantly “refreshed”, the old Mark being erased quickly. We must also not forget that the Earth’s surface is primarily occupied by the oceans, and always has been. therefore statistically more likely than a meteorite Compared to a continent one falls into an ocean, thus leaving little or no trace.

200 km. Approximate blocks of several meters over

The main crater at the origin of Wyoming’s secondary crater has disappeared. Thanks for calculating the trajectory and numerical simulation, the scientists managed to model the formation of the craters and trace the location of the main crater. their results published in bulletin of Geological Society of America, suggest that the main crater, now buried under smaller sediments, was originally 50 to 65 kilometers in diameter. The meteorite impact would have ejected blocks of four to eight meters wide by more than 150 to 200 kilometers wide, creating a secondary crater region. Thus the debris still formed unorganized sediments a . would have killed Speed 700 to 1,000 m/s.