A 200-kilogram (440-pound) fragment of the Canyon Diablo meteorite that was found at Meteor Crater in Arizona

A 200-kilogram (440-pound) fragment of the Canyon Diablo meteorite that was found at Meteor Crater in Arizona. Tens of thousands of Canyon Diablo meteorite fragments were found at Meteor Crater, the largest of which weighs 227 kg (about 500 pounds), but most fragments are much smaller than this sample. The meteorite struck at an approximate speed of 7.5-12.5 miles per second (12-20 kilometers per second) approximately 50,000 years ago. Clair Patterson from the California Institute of Technology (Caltech) used lead isotope data from a fragment of the Canyon Diablo meteorite and calculated an age for the Earth of 4.55 billion years (± 70 million years). This age has remained largely unchanged since he published the results of his measurements in 1956 in a journal paper titled: “Age of Meteorites and the Earth”.