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.
What really happened is that those prehistoric men were actually much smarter than we thought and were playing around with antimatter...
Please stop repeating lies.
There is not a "lack" of "metallic residue", just less than would be produced by a single large meteoritic impact, and of a different type than would be produced by a faster impact.
There's still plenty of iron from the meteor all over the place, though -- the plain around the crater is littered with it and people have been collecting pieces for over a century, but there's still a lot left.
To you.
Some folks here on FR could probably come up with a better explanation than this study! LOL!!!
Go for it. Make sure it matches all the observations and evidence in and around the crater to a high degree, as well as is consistent with all the known laws of physics -- like this one is.
Anybody who was close enough to see the fireball. They have drilled looking for the main body of the meteorite, but there is apparently no main body. The energy of a kinetic impact like this is underrated. It could vaporize the meteorite and create a lot of ionization of the resulting gas. The flash of impact would be like a nuclear explosion.
Look carefully at the pictures and you will see this.
No you haven't.
Any date is an article amounts to the personal wilda$$ guess of the first scientist they talked to and is subject to being changed with every additional person asked.
Wow, this is such a load of complete horse manure. You really don't have any idea how such dating is actually done, so you just make up whatever pops into your head about how it "must" happen, eh?
What annoys me is not that I have some pre assumed age of the earth and reject all else out of hand. What annoys me is that articles always toss out a date like that as a proven fact when it is simply and vague estimate based on whichever model (of many to chose from) the leading researcher on that site decided to use.
Posting your fantasies about the process again, eh?
I always laugh when someone tries pretend dates articles toss out are actually well proven and that questioning them is some how a sign of ignorance or delusion.
Proverbs 29:9: "If a wise man has an argument with a fool, the fool only rages and laughs, and there is no quiet."
Complete BS. The dating for this was probably done in several ways with widely different results and they simply averaged them or picked the one they 'thought was most reliable' (liked best).
At least this time you finally slipped and used a word ("probably") that clearly indicated that this *is* just your fantasy, and not based on any actual knowledge...
Before you attempt to critique something, make sure you actually have working knowledge of it first.
Craters are 'supposed' to be round, which is why Hoagland sees inner Buksminster Fuller structure in Iapetus. If a crater has straight sides, it must be something in the underlying terrain that gives preferential direction to the excavation. Fault lines would do it.
NO! Its the results of John Kerry's election campaign;-)
I've been proposing for some time now that JR create a Science forum.
That might cut down on some of the repeat nastiness every time any science is posted.
I doubt if the science folks go to the supernaturalist forum to spread venom.
I wonder if the opposite would be true if there were the two distinct forums?
I am not as ready to accept that the meteor landed right smack dab in the middle of a set of fault lines laid out on a checkerboard square pattern.
One fault line which would produce a distorted circle, or two parallel ones which would produce a distorted oval I could accept, but the symmetry of the square pattern is very great. A hit somewhere other than in the middle of a square (very, very rare) geologic formation would be expected to produce a crater of a different shape.
I can not think of any other square geologic formations on that scale anywhere on earth--can anyone else?
That's no crater, man. That originally was going to be our professional football stadium, but they would have to move the whole city of Glendale out there, so we finally decided to build on closer to town.
It might be that on the scale of the excavation there are many fault lines of approximately the same period, and they would run in the direction of crustal movement as well as perpendicular. Small craters tend to be round. Big craters would depend on the nature of the underlying structure. The earth's crust need not be uniform in all directions.
They think it's about 50,000 years old,give or take 50,000 year.
Kewl, thanks!
They make these dates up, IMO.
The crater is an obvious phony.
Why would it land EXACTLY at the end of that road, huh? answer that one smart guy !!!!
It's between Flagstaff and Winslow, AZ. Get in touch with the tourist Dept first - there's a lot of things to do/see in No. AZ including flyfishing for native trout or skiing, depending on the season you go.
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