Skip to comments.Arizona Meteorite Crater Mystery Solved
Posted on 03/09/2005 10:19:19 AM PST by ZGuy
It's a mystery that has puzzled scientists for years but researchers said Wednesday they have discovered why there isn't much melted rock at the famous Meteor Crater in northern Arizona.
An iron meteorite traveling up to 12 miles per second was thought to have blasted out the huge hole measuring three-quarters of a mile across in the desert.
The impact of an object at that speed should have left large volumes of melted rock at the site. But British and American scientists said the reason it didn't was because the meteorite was traveling slower than previously estimated.
"We conclude that the fragmented iron projectile probably struck the surface at a velocity of about 12 km (7.5 miles) (per second)," said Professor H. Jay Melosh, of the University of Arizona, in a report in the science journal Nature.
Meteor Crater, which was formed about 50,000 years ago, was the first terrestrial crater identified as a meteorite impact scar.
Melosh and Gareth Collins, of Imperial College London, used a simple model to calculate the speed on impact. They showed the meteorite had slowed when it hit the Earth's atmosphere and broke into fragments before it struck the Earth.
They calculated the impact velocity was about 26,800 miles per hour.
"Even though iron is very strong, the meteorite had probably been cracked from collisions in space," Melosh said in a statement.
"The weakened pieces began to come apart and shower down from about 8.5 miles high. As they came apart, atmospheric drag slowed them down, increasing the forces that crushed them so that they crumbled and slowed more," he added.
The scientists said that at about 3 miles altitude, most of the meteorite was spread in a large cloud.
It's pretty much in the middle of no where, but if you can get to see it, it's quite something.
You can look off to the south from the major highway going by it, and see a bowl shaped 'mountain' off in the distance. I've driven the way several times, quite amazing.
Only went over to look into it once. Awesome crater.
He ran the earth right into that asteroid.
Sorry, but even at 7.5 miles/second, it came and went in the blink of an eye. And it was before my time.
View from 27,000 feet.
I get my kicks on Route 66. I thought the mystery was the old "Spanish Mission" building along old Route 66 (current I-44, iirc) about a mile north of the crater.
Seems some conman ran a gas station from the "Spanish Mission". He had an observation tower about 25' high, from which he claimed you could see into the crater. (You couldn't). Since the human capacity for self deception is almost unlimited, most people managed to convince themselves that they had "seen the crater" and went on.
If the mark complained, he would tell them to take their ticket to the privately run (and for profit) meteor museum and they could look from there. Of course the museum did not honor his tickets, again many folks would chalk it up to experience and move on. If they returned and demanded a refund, he would grant it, out nothing but the cost of a cheap ticket.
Agreed. Only went to it once, thirty-odd years back, but the impression it left in my mind is still fresh.
But then. most of Arizona (that I've seen, anyway) is pretty amazing.
Now at least I can finally get some sleep.
Liberals would have put the earth in a lock box to protect it.
What makes them think it was 50,000 years ago?
And are there any?
Before or after the main impact site? Any astrophysicist(s) out there that can enighten me?
I actually have to say I was pretty dissappointed to pay the rather high admission price and see little more than an unimpressive hole in the ground. The idea of seeing where a meteor struck the Earth is more exciting that the actual thing. Perhaps because I'd been at the Grand Canyon (for free) the previous day, this thing didn't seem worth the detour off the freeway. If you've seen the pictures above in this thread, you've pretty much seen all you need to see.
Okay. I'm a bit slow.
If what they say in this sentence is the case.....why is there a hole? That is deeper in the middle...?
The cloud made the hole, I suppose..........? Just asking...
It's not far from Flagstaff, where you can visit the Lowell Observatory (they have public tours), a couple of hours from the ever-popular south rim of the Grand Canyon, and not far from Sedona and many interesting Indian ruins (Montezuma's Well, Montezuma's Castle). GREAT vacation spot, if you can't make it to New England.
Sure that's not Amboy Crater in CA?
It truly is an impressive sight.
Near Winslow, AZ I believe.
A "Craterism" ping.
Uh, that's not Meteor crater... it's a cinder cone (volcanic). Don't know where. From a distance, Meteor crater has a much lower, more subtle topographic profile.
I think it one of the natural wonders, a geological "must see". Definitely worth a half day side trip when seeing the Grand Canyon.
Look it up. You know what Google is.
It's a matter of faith.
Good luck getting them to admit it, though.
The site I pulled the pic from identifies it as Meteor Crater in Arizona. I've never been there so I'm just taking him at his word. It does look a little tall and not as wide in that shot compared to the others though...
My thoughts too, if it was mostly vaporized (in cloud form) then why is there a big 'ol hole in the ground? and the article did not really explain what happened to the iron either, seems like they would have found more.....
I already know what most of the "geochronical indicators" are. I want to know which ones they relied on in this case.
They never tell you in the popular press, they always leave that out.
Another extremely interesting feature your son might get into is called Upheaval Dome in Arches National Park, Utah. It is a large circular anomaly that for a century was thought to be the surface expression of a salt diapir (a large blob of salt that migrates upward due to bouyancy). A few years ago grad student reexamined it and determined it to be a meteor impact feature. It is easy to get to, and their is a nearby topographic high so you can get a good view of the thing.
It was wearing a Timex. It didn't stop ticking.
That's Amboy Crater. We used to ride dirtbikes out there back in the 60's and 70's. Had my first tangle with a rattlesnake within view of that crater.
>>The scientists said that at about 3 miles altitude, most of the meteorite was spread in a large cloud.<<
So it was a shotgun blast?
It's a matter of some fairly complex, but well tried and tested, chemical and radiological techniques.
Your average mainstream media science article isn't going to take about 10 pages filled with chemical formulas explaining how rocks and fossils are dated EVERY single time they mention some date from a scientist that annoys some idiotic Young Earth Creationist because it's older than 6,000 years.
In terms of the popular press probably the most extensive and understandable explanation of dating of rock is in the "Crossing the Craton" section of John McPhee's "Annals of the Former World."
And while you're there (Winslow), you can stay at the very nicely restored La Posada, a hotel left over from the great coast to coast railroad days. Designed by Mary Jane Coulter (no photos needed of that Coulter).
The trestle bridge over Diablo canyon is close and worth a side trip as well.
Yep, he musta been driving drunk and on his way to buy cocaine while he was AWOL from the TNG. Yep, that's it.
The suspicion that the crater is only 50,000 years old, giver or take about 3,000 years, comes from the fact that it is not terribly weathered. Anything over 100,000 years would be much more worn down or even obliterated.
Fortunately, the climate is fairly dry in that area, so the weathering influence comes mainly from the action of wind and sand, and not so much from rain, which can do much more damage to such a site.
In short, the age determination is rough, and more a process of elimination: no more than 100,000 years, and no less than 20,000 (and certainly more than 6,000 years) based on the amount of weathering and the amount of debris buildup in the bottom of the crater.
Hope this helps.
So this crater is formed by multiple meteorites, huh? Would you scientists like to try again?
Studies like this are so pitifully stupid!
Sometimes there are no explanations for phenomenom like this.
Man, (the species) in general wants to say they understand everything in the world.
Somehow........it's just not that important.
Tax dollars are used for this group, I would imagine.(rolling my eyes)
Article wasn't that clear and I think people are misunderstanding what was said.
It wasn't a wide scattering of multiple meteorites...what they're saying is it wasn't a coherent big block when it hit; it was a grouping of pieces that were all right next to each other.
Good thing it is in the middle of nowhere. It would have been disastrous if it hit a city or something.
Yes, I am kidding.
Regardless of theories, the meteor strike blasted rock and bits of itself (nickle-iron) for miles. Owners of surrounding ranches still find pieces which they sell to rock shops. My sample weighs several ounces.