A very unusual cluster of multiple small impact craters probably created by the impact of a split cometary nucleus in Patagonia

ROCCA, MAXIMILIANO; ACEVEDO, R.D.

Historia Natural

Fundación Félix de Azara

Año: 2019 vol. 9 p. 5 - 15

0326-1778

An analysis of the impact event that created the Bajada del Diablo (S 42º 45?, W 67º 30?)impact crater strewn field is presented. At mid Pleistocene (780,000 to 130,000 years ago), about 550 impact craters of less than 400 meters in diameter were created simultaneously in an area of about 480 square kilometres at Bajada del Diablo in central Patagonia. Absence in the maps of craters of a clear dispersion ellipsoid in the area points toward the idea of the impact of a very fragmentedsmall cosmic object. Cosmic impactor could have been: 1) a ?rubble pile? type Near Earth Asteroid or 2) a small split cometary nucleus. The absence of meteorites in the area is in conflict with thehypothesis of the impact of a rocky Near Earth Asteroid. More probably, an ice comet nucleus was the responsible of the impact since the impact of such an icy object would not have left visible tracesof itself after more than 130,000 years. After some analysis the impact of a small 200 meters wide split ice comet nucleus is presented as the most probable scenario.