An Impact Site: Meteor Crater

speed sign

How fascinating can a big hole in the ground be?  Quite!!

When it’s a hole like we found at Meteor Crater, 35 miles east of Flagstaff. aerial view of crater

Over the years there was speculation that this was a volcanic site, but thru various scientists and explorations it was finally confirmed that a meteor created it.  It is the first proven, best preserved impact site on our planet.

Daniel Moreau Garringer (1850-1929) “began his quest (1903) to prove that this unique natural landmark was caused by the impact of an object from outer space.

“A practicing mining engineer and geologist, inquisitive and principled by nature, he spent the remaining twenty-six years of his life endeavoring to convince the scientific community and others of the truth of his Impact Theory.  His persistence in the face of strong opposition eventually laid the groundwork for a new field of science called Meteoritics.  His theory of meteorite impacts, both here on Earth and on the moon, is now universally accepted, and scientists believe that much of the solar system was affected by such impacts.” (Memorial sign for Daniel Moreau Barringer, @ Meteor Crater)

Eduardo

Eduardo

Eduardo took us on a short walking tour of the rim of the crater along with people from all over the States, and a multi-generational family from Venezuela.  Eduardo gave us the history and geological information of the site in layman’s terms so we could understand most of it.  But so typical…I can’t recall it all.

Telescopes, welded into place so you can spot a particular object of interest.

Telescopes, welded into place so you can spot a particular object of interest.

A Rock the size of a small house.

A Rock the size of a small house.

Traveling at 64,000 km/hr or 40,000 mi/hr—that’s 18km or 11 miles/second!—a meteor coursed through the skies and smashed into the plateau.  Within seconds there was a tumultuous explosion, obliterating the meteor itself, throwing millions of tons of rock across the land and opening up a crater about 1.5 km across, nearly 3 km around, and they figure it was about 210 meters deep (700 ft), though about 150 ft of that has since been filled in due to erosion.

They speculate that it was a rock the size of about ½ this parking lot:

Half the size of this parking lot is what they calculate the size of the meteor that created this crater.

Half the size of this parking lot is what they calculate the size of the meteor that created this crater.

weight

Numerous attempts have been made to locate any meteorite mass left behind, but the impact had such a force in excess of 20 million tons of TNT, there was nothing left behind. Impact chart

It displaced billions of tones of rock, flipping some of the geological layers upside-down as it were.  Where the layers had been dark brown-beige-white going from surface deeper down, now those layers were inverted on top of the surrounding ground. So now there is white on top with a layer of beige below that, all on top of the dark brown that used to be the surface.

Johnson tribe

Johnson tribe

Made to look like the kids are at the bottom of the crater, but public isn't allowed down there.

Made to look like the kids are at the bottom of the crater, but public isn’t allowed down there.

This Holsinger Meteorite was discovered about 2 miles from Meteor Crater.

Kids touching the Holsinger meteorite weighing 1,406 lbs

Kids touching the Holsinger meteorite weighing 1,406 lbs

Imagine, we were touching something that came from outer space!  Cool thought.

It is believed to have broken off of the meteor that hit here.  This fragment weighs an amazing 1,406 pounds, made of 92% iron, 7% nickel and 1% trace minerals.  These metallic meteors don’t break up in the atmosphere as frequently as stony meteors so they can remain quite large, and are very dense.

The holes and ridges were formed on the meteorite from the extreme friction and heat created while it traveled at such high speeds through our atmosphere.  It would have entered our atmosphere attached to the parent meteor and then broke off and landed as a separate piece near Flagstaff.

There are five sources of meteors:

-Fragments created from collisions within the Asteroid Belt

-Impact and the subsequent fragmentation of other masses

-Fragmentation of Comets

-Internal breakup of former planets

-Sources yet unknown to mankind

We watched a short video called B612, about technology that is already available to track meteors in space, to know when they might be on a collision course with Earth and be able to knock them off their path so that there wouldn’t be any impact.

Every day there is about 1,000 tons of meteoritic material that falls to the Earth but most of it goes unnoticed since they land in remote areas or in the oceans.

Most of these meteors are small enough to be slowed down by the atmosphere and then they drop harmlessly to Earth’s surface.

But that doesn’t always happen.  Periodically a large meteor impacts us!

Hoba meteorite, largest in existence.  Measures 3m x 3m x 1m.  Still lies half-buried in Namibia.

Hoba meteorite, largest in existence. Measures 3m x 3m x 1m. Still lies half-buried in Namibia.

The Williamette meteorite, discovered in Oregon.  This is the largest meteorite found in the USA.

The Williamette meteorite, discovered in Oregon. This is the largest meteorite found in the USA.

Meteor Crater is speculated to be from 50,000 years ago.  Image the damage a meteor the same size could do today if it were to hit a populated city?  Not only is there damage creating a massive hole, but the velocity at which a meteor would travel through our atmosphere creates a shockwave felt far and wide, and winds of enormous speed that could wipe out surrounding forests or buildings.  The devastation would be massive.

Because of similarities between this crater and the moon’s craters, astronauts were trained here between 1963 and through late 1970.  The astronauts learned how to maneuver around a cratered environment, how to collect & identify rocks that would have been ejected from a crater at impact.  This would later provide clues to the underground composition of the moon.

They learned how to tell the difference between a crater created by a meteor and one formed by volcanic activity.

It was at one of these training sessions when one of the astronauts ripped a hole in their suit on one of the rocks in the crater.  This led to redesigning of the suits with a thicker material to better resist tears, for if this tear had of occurred while in space, we would have had the first moon fatality.

The command module is the only portion of a spacecraft that returns to Earth, glowing red as it enters the Earth’s atmosphere much like a meteor.  This capsule is named Boiler Plate 29A,

capsule family

and has never gone into space. It was created in 1965 to test the systems that helped Apollo space capsules float upright at splash-down at sea.

Not sure why the space module is here…maybe just to remind us that space programs have benefited from training here at Meteor Crater.

Toveli and Gaelyn enjoyed “Make Your Own” impact simulation, changing the velocity, the angle of impact, the diameter of the rock, etc.  The damage a meteor causes as it slams into the ground depends on several factors such as worked into the simulation.  Fast, large heavy meteors that enter the atmosphere at a steep angle usually cause the most damage.  Scientists believe that the meteor that hit here approached from the east at a 60 degree angle.  Moving at high speeds, it could have been seen in the sky over Paris just 8 minutes before crashing into this plateau in what we now call Arizona.Tov @ Make Your Own Impact

Here’s a map of the Gulf of Mexico, where scientists Walter and Luis Alvarez suggested that a huge meteorite about 10 km in diameter hit Earth in the Caribbean Sea off the east coast of the Yucatan Peninsula. Yucatan mapIt threw so much debris, dust & water up into the atmosphere that it blocked sunlight for months.  This would have disrupted the growth of plants, and send the entire food chain in to disarray.  There may have been flash fires set off (as the theory goes) all over the planet that added huge amounts of soot to the atmosphere.  This ‘impact winter’ is speculated to have spelled doom for T-Rex and other Cretaceous-era species.

It was a full and exciting morning for our tribe to tour Meteor Crater.  It isn’t just any hole that can capture our attention for more than a moment.

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