If you happen to find yourself in the neighborhood of Flagstaff, Arizona, I’d highly recommend a side-trip to see Barringer Crater (a.k.a. Meteor Crater). It’s only about 56 km (35 miles) east of Flagstaff, and not terribly expensive to visit. Some 50,000 years old, it’s also said to be the best-preserved meteor crater on earth.
If you were curious about what a meteor crater rim would look like from the outside, this is that very view for Barringer Crater from its access road (it has its own exchange off Interstate 40). If you didn’t know any better, you could drive right past it, thinking this was just a low line of hills.
The crater is named for Daniel M. Barringer, a mining engineer who in 1903 first suggested that it may have been caused by a meteor impact. But solid proof of this was not in hand until 1960, when Gene Shoemaker discovered shocked silica in the crater — something not otherwise seen on earth, except in craters left over from nuclear test explosions. While many impact craters have since been found on the earth’s surface, Shoemaker’s discovery means that Barringer Crater holds the title as being the first definitive evidence of impacts on earth.
You might also want to revisit my earlier post on the crater, from all the way back in 2008.