Meteor Crater is nearly a mile across, 550 feet deep, and almost perfectly circular - a textbook example of what happens when a cosmic visitor arrives at 26,000 miles per hour. Fifty thousand years ago, a 150-foot nickel-iron meteorite struck the Arizona desert with the force of 10 million tons of TNT. The impact vaporized the meteorite and excavated 300 million tons of rock in seconds. For decades, scientists debated whether the crater was volcanic; mining engineer Daniel Barringer was certain a meteorite was responsible - and spent 27 years and $600,000 drilling for a metallic mass that had already vaporized on impact. The crater that bears his name proved him right about the impact, wrong about the buried treasure. NASA trained Apollo astronauts here; the crater remains the best-preserved impact site on Earth and a reminder that the cosmos occasionally delivers special delivery packages.
The Canyon Diablo meteorite (named for a nearby canyon) was traveling at approximately 26,000 miles per hour when it hit. The energy released - equivalent to about 10 megatons of TNT - vaporized the meteorite and melted the underlying rock. The explosion excavated a crater 4,000 feet across and 700 feet deep (it has since partially filled with debris). The rim rose 150 feet above the surrounding plain. The shock wave flattened everything for miles. Fragments of the original meteorite - some weighing thousands of pounds - scattered across the surrounding desert. The main mass, however, was gone - converted to gas in the instant of impact.
European Americans discovered the crater in 1871, but its origin was debated for decades. Grove Karl Gilbert, the leading geologist of his era, visited in 1891 and concluded it was volcanic - he couldn't find the meteorite mass he expected. Daniel Barringer, a Philadelphia mining engineer, disagreed. In 1903, he acquired the crater and began drilling, confident that millions of tons of valuable iron waited underground. He drilled for 27 years without success. What Barringer couldn't know - what scientists didn't yet understand - was that an impact at cosmic velocities vaporizes the impactor. He died in 1929, still believing the mass was there.
Eugene Shoemaker proved the crater's impact origin in the 1960s. He found coesite and stishovite - minerals formed only under extreme pressures far exceeding anything volcanic - in the crater rocks. This was the smoking gun: proof that the crater was created by hypervelocity impact, not volcanism. Shoemaker went on to pioneer the study of impact craters on Earth and other planets. The crater that Barringer had devoted his life to proving was an impact was finally vindicated, though not in time for Barringer to know. The site is now officially called Barringer Crater, though most people know it simply as Meteor Crater.
NASA recognized Meteor Crater's value for astronaut training. In the 1960s, before the Moon landings, astronauts practiced at the crater, learning to recognize impact features they would see on the lunar surface. The crater provided the best Earth analog for lunar terrain. Apollo astronauts trained here, walking the rim and studying the geology. The crater remains important for planetary science, providing a laboratory for understanding impacts that have shaped every body in the solar system. Gene Shoemaker's ashes were carried to the Moon on the Lunar Prospector mission in 1998.
Meteor Crater is located off Interstate 40 about 40 miles east of Flagstaff, Arizona. The site is privately owned (still by the Barringer family) and charges admission. A museum interprets the science of impacts and the crater's history. An observation deck on the rim offers views into the crater. Guided rim tours are available. A piece of the original meteorite is on display and available to touch. The crater itself cannot be entered - it's too dangerous and too fragile. The surrounding desert is scenic but barren; facilities are limited to the visitor center. Flagstaff Pulliam Airport (FLG) is the nearest airport. The crater is often combined with visits to the Painted Desert, Petrified Forest, or Grand Canyon.
Located at 35.03°N, 111.02°W in the Arizona desert, 40 miles east of Flagstaff. From altitude, Meteor Crater is unmistakable - a nearly perfect circle punched into the flat desert, surrounded by an elevated rim. The crater is about 0.75 miles in diameter. The geometric perfection distinguishes it from volcanic craters. The visitor center is visible on the north rim. Interstate 40 passes a few miles to the south. The painted desert landscape stretches in all directions. Apollo astronauts saw this view before seeing similar craters on the Moon.