The asteroid fell about 50,000 years ago.[3] The meteorites have been known and collected since the mid-19th century and were known and used by pre-historic Native Americans. Meteor Crater, from the late 19th to the early 20th century, was the center of a long dispute over the origin of craters that showed little evidence of volcanism. That debate was largely settled by the early 1930s, thanks to work by Daniel M. Barringer, F.R. Moulton, Harvey Harlow Nininger, and Eugene Shoemaker.[4][5][6][7][8][9][10]