METEOR CRATER 1
Arizona's Meteor Crater is the youngest and best-preserved meteorite crater on the Earth. Meteorites fall onto the Earth every day, but very rarely is one large enough and strong enough to pass through the atmosphere without being slowed down. The Meteor Crater meteorite was iron-nickel metal, and is estimated to have been ~50 meters in diameter, and have weighed several hundred thousand tons. It hit the Earth at a speed near 20 kilometers per second (~50,000 mph), and excavated the Meteor Crater in a few seconds. Meteor Crater was first described by white folk in 1871 and named Franklin's Hole. Settlers in the area renamed it Coon Butte. Geologist G.K. Gilbert, who first interpreted the Moon's craters as impacts, studied Coon Butte and decided it was most likely a maar crater, from a volcanic explosion. In 1902, Daniel M. Barringer, a New Jersey steel magnate, investigated the site as a possible source of iron, and became convinced that it was a meteorite impact crater. His work yielded no iron mine, but finally swayed scientific opinion.
Meteorite impact cratering is the most important geologic process that shapes the surfaces of solid
planets and moons. Impact crater like Meteor Crater (and MUCH larger) are abundant on Mars and most
other planets and moons). Impact craters are rare on geologically active places like the Earth,
Venus, and Jupiter's, but not because meteorites never hit there. Impact craters formed on all of
the planets and moons, but were covered over by lava flows (especially on Venus and Io) or
erased by erosion and plate tectonic processes (on Earth).
