History
The asteroid fell about 50,000 years ago. The meteorites have been known and collected since the mid-19th century and were known and used by pre-historic Native Americans. The Barringer Crater, from the late 19th to the mid-20th century, was the center of a long dispute over the origin of craters that showed little evidence of volcanism. That debate was settled in the 1950s thanks to Eugene Shoemaker's study of the crater.
In 1953, Clair Cameron Patterson measured ratios of the lead isotopes in samples of the meteorite. The result permitted a refinement of the estimate of the age of the Earth to 4.550 billion years (± 70 million years).
Read more about this topic: Canyon Diablo (meteorite)
Famous quotes containing the word history:
“Humankind has understood history as a series of battles because, to this day, it regards conflict as the central facet of life.”
—Anton Pavlovich Chekhov (1860–1904)
“All history becomes subjective; in other words there is properly no history, only biography.”
—Ralph Waldo Emerson (1803–1882)
“Let us not underrate the value of a fact; it will one day flower in a truth. It is astonishing how few facts of importance are added in a century to the natural history of any animal. The natural history of man himself is still being gradually written.”
—Henry David Thoreau (1817–1862)