Feature Articles – Massive impact
The possibility that our civilisation can be wiped out by a sudden meteor strike is a reality we have only slowly and recently come to embrace. And it is at Meteor Crater, just outside of Flagstaff (Arizona), that we can see some of the best visual evidence of one such an event.
by Philip Coppens
In the late 1990s, “Deep Impact” and “Armageddon” were smash hit movies. The art of cinema visualised that what the mind had difficulty to imagine – and which, if we are to believe Immanuel Velikovksy, our ancestors as a whole at one point tried to wipe from their memory, as our roughly 17 by 14 centimetres brain was incapable of holding it. Velikovsky argued that such stellar impacts had occurred only a few thousands of years ago, had caused the demise of civilisation and traumatised entire populations.
The official stance of science is that there is no such thing. We’ve been told that sauch things do exist, but not in recent millennia. A massive meteor impact 65 million years ago largely wiped out the dinosaur age – even though some survived. We cannot see the impact crater, as it impacted in the Gulf of Mexico. But it is in the nearby state of Arizona that another famous crater exists: Meteor Crater. On a geological level, the impact that created Meteor Crater would have been similar to a mosquito hitting a human being, and leaving a tiny bite. Equally, the Earth’s crust felt the impact, but the Earth as a whole, would not have made much of this. The proof, as they say, is in the scar: Meteor Crater. The impact produced a massive explosion equivalent to at least 2.5 megatons of TNT – equivalent to a large thermonuclear explosion and about 150 times the yield of the atomic bombs used at Hiroshima and Nagasaki. The explosion dug out 175 million tons of rock. For humans – of which there were preciously few if any in this region 50,000 years ago, when the impact occurred – it would have been devastating. For the resident animals, it no doubt was. All life within a radius of three to four kilometres would have been killed immediately. Severe flash burns would have been experienced up to 10 kilometres, with a shock wave levelling everything within a radius of ca. 20 kilometres. Limestone blocks as massive as thirty tons were tossed outside the crater’s rim, and debris from the impact has been found over an area of 100 square miles. The shock of the impact would have produced a localized earthquake of magnitude 5.5 or higher. Today, the visitor centre at Meteor Crater tries to underline this message: it allows you to “dial up” a meteor impact, whereby you can choose whether it will create minimal or earth-destroying impact.
This attraction is just off Interstate 40, near Flagstaff. It is a “blip on the horizon”, as one travel writer described it: its rim is only fifty metres above the flat scrubland, and though you can see it from the Interstate, it is nothing too impressive. If anything, the surrounding desert and the San Francisco Peaks are utterly more beautiful and impressive. And visitor attraction wise, the not too distant Painted Desert and Petrified Wood National Park are far more popular – and beautiful – too. But these geological features were made over the course of millennia, whereas Meteor Crater was made in a matter of seconds. And who said that such harbingers of death have to be “beautiful”? Meteor Crater therefore shows the hard evidence of what the above science fiction movies tried to portray: a deep impact. Once on top of the rim, one can see a 175 metres deep crater, more than one kilometre across. If a football game were to be played inside the crater, there would be adequate seating for two million fans.
Interestingly, the crater is no stranger to science fiction, as in 1984, it was used as the backdrop for the science-fiction movie “Starman”, featuring Jeff Bridges and Karen Allen. The characters come to the crater to meet an extra-terrestrial ship, and of course, to some extent, a meteor is indeed an extra-terrestrial ship, if only because it is now recognised that meteors likely carry viruses and bacteria – life – and might indeed have been responsible for bringer the building blocks of life – RNA (linked with DNA) – to Earth. Equally, the crater was used as training ground for the astronauts part of the Apollo moon landing missions. Of course, some argue that some of the faked footage was actually shot there, as some believe we never made it to the moon.
In short: Meteor Crater provides easy-access, highly visual “in your face” proof that meteors are not just the stuff of CGI, but real. That there is truly nothing we can do if something like this were to hit us again. And “this” was nothing more than a fifty metres lump of iron and nickel, a gift sent to Earth from the asteroid belt that sits between Mars and Jupiter. It is no doubt a cosmic trickster coincidence that nearby Flagstaff hosts the Lowell Observatory, named after astronomer Percival Lowell, who spent years studying Mars, convinced he saw canals there – though he was also the person who discovered Pluto. And only an hour’s drive from Meteor Crater are the Hopi Mesas, the heartland of the local Native Americans, whose religion is replete with astronomical connotations. Some of their ancestors’ sites are even said to have recorded supernovas. The Native Americans must have come across Meteor Crater, but an interesting question is whether they saw it for what it was, or considered it to be a volcano. For this debate was precisely the one held some decades ago. Though undoubtedly known by the Native Americans, the first recorded mention of the crater by white people occurred in 1871. Dr Clyde Fisher relates that a shepherd named Mathias Armijo in 1886 found a piece of iron west of the crater near Canyon Diablo and thought it was silver. In 1891, the crater was then misidentified as the crater of a volcano. Only at the start of the 20th century did mining engineer Daniel Barringer suggest that a meteor might have been responsible for the crater.
The early misidentification could have been for a number of reasons: one, Sunset Crater nearby is indeed the remains of a volcano, one of several in the region; and there is the general reluctance of people to ponder the notion that we – and Earth – could be gone in an instant.
Inside the crater can still be seen a boiler and steam-powered winch. They are the remains of Barringer’s three decades’ long quest to find the iron remains of the meteor – evidence that would prove him right immediately, though Barringer was not so much out for scientific recognition, as the income he would get from selling the material. He had estimated that given the size of the crater, there was a potential 100 million tons of iron. (Today, the estimate is that the meteor only carried 300,000 tons.) Iron ore of the calibre found at the crater was valued at the time at $125 per ton. He thought he might therefore have a potential $12.5 billion in earnings if he could discover it. (At 300,000 tons, earning $37.5 million is still a respectable sum of money.) No wonder therefore that he dug an impressive 419 metres down, but he never found the ore and today, the consensus is that most of the meteor vaporised on impact, though some believe that there is still 150,000 tons of meteorite under the crater’s south rim, which shows signs of uplift. Since Barringer gave up his quest in 1929, no-one has dug since. Relatively large chunks of nickel-iron fragments, ranging from gravel size to blocks weighing up to 640 kilograms have been recovered from the debris field surrounding the crater. Barringer’s battle with science is interesting, as they were unwilling to consider the role meteorites had played in shaping terrestrial geology – as well as potentially defining history. Though some scientists themselves might argue this was merely because Barringer introduced a new subject matter, the fact of the matter is that the surrounding plains were covered with about thirty tons of large oxidized iron chunks from the meteorite, thus clearly proving that a meteor impact had occurred, and that the crater was a meteor crater – despite the absence of the large iron core itself.
Many geologists remained sceptical of the crater’s meteoritic origins until as late as the 1950s, even though its cause had been championed by the likes of Professor Herman Leroy Fairchild, an early promoter of the idea of meteorite impact cratering. It was not until 1960 that the infamous Eugene M. Shoemaker (of comet fame) would confirm Barringer’s conviction that the crater was meteoric in origin. In the end, the presence of the minerals coesite and stishovite, rare dense forms of silica found only where quartz-bearing rocks have been severely shocked by a large meteorite impact, was what won the argument – volcanoes were unable to create these minerals.
Shoemaker’s discovery caused a sensation in the geological world, as it was the first definitive proof of an extraterrestrial impact on the Earth’s surface. Since then, numerous impact craters have been identified around the world. In fact, the second suspected meteor crater was recognised in 1926, 21 years after Meteor Crater, in Odessa, Texas. Today, there are 175 known meteor scars on Earth, but Meteor Crater is one of the most famous and most easy to visit. The dry climate that reigns over this region has also caused little erosion. Travel guides to Arizona highlight Meteor Crater, but don’t list it as a must. Instead, they argue that the Grand Canyon and Monument Valley are far more important to your visual sense than Meteor Crater. Though they are right, they also miss the point: Meteor Crater is literally on par with the biblical warnings that God could strike whomever down – Sodom and Gomorrah for example – in an instance. Meteor Crater proves you don’t need God’s wrath to create instant death; sheer coincidence will be able to achieve just that, just as well. This article appeared in Atlantis Rising, Issue 78 (November – December 2009).