Controversial Impact Crater Under Greenland's Ice is Surprisingly Ancient (science.org) 38
An anonymous reader shares a report: In 2018, an international team of scientists announced a startling discovery: Buried beneath the thick ice of the Hiawatha Glacier in northwest Greenland is an impact crater 31 kilometers wide -- not as big as the crater from the dinosaur-killing impact 66 million years ago, but perhaps still big enough to mess with the climate. Scientists were especially excited by hints in the crater and the surrounding ice that the Hiawatha strike was recent -- perhaps within the past 100,000 years, when humans might have been around to witness it. But now, using dates gleaned from tiny mineral crystals in rocks shocked by the impact, the same team says the strike is much, much older. The researchers say it occurred 58 million years ago, a warm time when vast forests covered Greenland -- and humanity was not yet even a glimmer in evolution's eye.
Kurt Kjaer, a geologist at the Natural History Museum of Denmark and a co-author of the new study, says the new date is at odds with the team's initial impression, gleaned from ice-penetrating radar. "But this is the way science works and should work," he says. The date is a blow to a group of scientists that for more than a decade has advanced a controversial hypothesis that the Younger Dryas, a drastic, 1000-year cooling about 12,800 years ago, was triggered when a comet struck Earth. They had seized on the first Hiawatha paper as a smoking gun: The crater seemed about the right age, and it was in the right place -- near a region of the North Atlantic Ocean that heavily influences Northern Hemisphere climate. Now, says Brandon Johnson, a co-author and impact modeler at Purdue University, West Lafayette, "It's probably safe to put the Younger Dryas impact hypothesis back to rest for a while."
Kurt Kjaer, a geologist at the Natural History Museum of Denmark and a co-author of the new study, says the new date is at odds with the team's initial impression, gleaned from ice-penetrating radar. "But this is the way science works and should work," he says. The date is a blow to a group of scientists that for more than a decade has advanced a controversial hypothesis that the Younger Dryas, a drastic, 1000-year cooling about 12,800 years ago, was triggered when a comet struck Earth. They had seized on the first Hiawatha paper as a smoking gun: The crater seemed about the right age, and it was in the right place -- near a region of the North Atlantic Ocean that heavily influences Northern Hemisphere climate. Now, says Brandon Johnson, a co-author and impact modeler at Purdue University, West Lafayette, "It's probably safe to put the Younger Dryas impact hypothesis back to rest for a while."
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65 million years to 58 million years may seem close together to us, but that's still a pretty wide spread of years even in geologic / astrophysics terms.
I'd be much more curious, if the new theory is correct, what impact it had on life on Earth. The planet would have been climbing back from the impact 65 million years ago, and perhaps this 58 million years ago impact set up a cascading effect that caused a new wave of sporadic death around the planet, and forced out more cold-blooded species around the plan
Controversial? (Score:4, Insightful)
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Are you seriously pro-crater or something?
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Not so much pro-crater as anti-anti-crater.
Shows what you know, thinking craters are real. Even an idiot like me can see a big amount of stuff drops outta the sky there will be more stuff, why is there a hole with less stuff? Checkmate object inpermenance believers.
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"How can an impact crater be controversial?"
Don't forget that some people believe the universe was created 6000 years ago, so impact craters older than that are a problem.
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I see no problem. The God-Wot-Did-It crowd will simply claim he made it that way, and all will still be well in their science-free world.
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Controversy not bad in Science (Score:2)
How can an impact crater be controversial?
Probably because the evidence for it is not clear cut. We do not live on the moon where craters are clear and obvious for millions of years. The Earth's natural erosion processes rapidly remove evidence of craters and so you have to look harder and infer their presence from more subtle clues. When the data are less clear-cut this can lead to disagreements between scientist with some convinced by it and others who are not.
Disagreements like this are a critical part of the scientific process since it moti
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How can an impact crater be controversial? AP style guides have ruined that word. The impact crater is a thing and it's presence is a fact. There can be controversy within the scientific community in trying to interpret what caused it, but the impact crater itself is simply a physical fact.
I mean, even the summary said what was controversial about it - the dating.
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The controversy around Younger Dryas is that the some people claim it was a near extinction event that wiped out advanced human civilizations that existed at the time. Mainstream science generally holds that there were no such things and that human technological progress has occurred in pretty much a straight line from the beginning of
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Mainstream science generally holds that there were no such things
That is wrong. Any such idea is debunked since 30 years: https://en.wikipedia.org/wiki/... [wikipedia.org]Ãbekli_Tepe
We pretty well know that there were several high level civilizations 12,000 years ago. We just do not know why/how they vanished. And there is no "main stream scientist" who is opposing that. Otherwise he had no degree.
and people who support Younger Dryas often believe those pyramids were inherited by an earlier culture that was wiped out
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30 years later, other archaeologists will uncover what they believe are examples of functional, properly formed HTML links from stories that predate this one. Their work will be attacked by the above group and they'll be labeled as quacks, because "we basically know who build it"
We've been hit before, and will be again. (Score:2)
It's just a matter of time before we're hit again with a large chunk of something from space. Now, whether or not we have the capabilities or political will to actually do something about it is another matter.
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Now, whether or not we have the capabilities or political will to actually do something about it is another matter.
You’re missing the bigger picture. There could be trillions of dollars worth of metal on one of those puppies, no scratch that, many times the metal humans have ever mined, so much as to redefine the worlds economy for centuries. Idiots kept saying we couldn’t have infinite exponential growth with limited resources and now those same people want to send this meal ticket away and not gorge upon its riches. Sending away good fortune away into deep space will be the death of the human race.
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So we park a bunch of big asteroids close to the earth? That requires a capability we don't have.
We send miners into the asteroid belt to mine asteroids? That requires a set of capabilities we don't have. I also think if we could economically mine asteroids on a wholesale level, the value of those minerals would probably become less and less making the cost of operations, i.e., labor etc. the biggest cost component. mechanical/remote mining would make it feasible to some level but this is the plot-line of s
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We blast them into a million pieces? We could probably do that now but the political willpower to use nukes would be an issue.
But think of how many people are living paycheck to paycheck and need jobs. Blasting it into many survivable pieces when it’s close and then harvesting it will create tens of millions of jobs the world over. Look, maybe a few of the smaller countries on the coasts might not survive, but there should be more than enough wealth to cut them in and spread around a bit to get general approval. Look, this has been well covered in a documentary, I didn’t watch the end but I’m sure it went swi
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Yup, the only trick is to get them materials from up there to down here without fizzling them away in the atmosphere in the process. Have you ever seen a mine here on this dirtball? Do you have any sense of scale?
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The moon also has plenty of resources and is far less difficult to target than an asteroid. There's still no practical or cost-effective way of getting any of those resources extracted and back to earth in a way that makes any kind of economic sense. The more realistic scenario is that those resources will be mined in-place once there's a human settlement in order to extend their own capabilities while reducing dependence on things that have to be shipped to them for basic upkeep. Even that seems unlikely t
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The point that made this clear to me is that, even if you managed to fill the space shuttle brim full of gold from space and land it on earth, the gold inside still wouldn't be enough to pay for the trip.
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The point that made this clear to me is that, even if you managed to fill the space shuttle brim full of gold from space and land it on earth, the gold inside still wouldn't be enough to pay for the trip.
Sure, because running the Space Shuttle was stupidly expensive. The economics look very different if SpaceX gets even close to their goals for Starship. Hell, the economics look drastically different even at Starship's initial cost when it is first deployed and operational. And unlike Shuttle, Starship will be able to land on Luna and come back with a payload, something which was physically impossible for Shuttle.
That's not to say that Lunar mining will be meaningful to Earthside economies any time this
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Ok, so how much will it cost? Starship isn't going to come back down to earth with a Space Shuttle load worth of gold.
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Ok, so how much will it cost? Starship isn't going to come back down to earth with a Space Shuttle load worth of gold.
Just drop it onto the planet, then it’s easy to mine. If you’re concerned about safety, keep it under a few cubic miles. What could possibly go wrong? Won’t someone think of the money?
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I mean, we ought to try it once anyway, just to be sure.
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Ok, so how much will it cost? Starship isn't going to come back down to earth with a Space Shuttle load worth of gold.
Which version of Starship?
Technically a Space Shuttle worth of Lunar gold is zero kilograms. But pretending for a moment that Shuttle had any way at all to reach Luna, land, lift off, and return, Space Shuttle's cargo capacity was officially 29,000 kg, but practically was 25,000 kg. Starship's cargo capacity is 100,000 kg. Underloading Starship to match means it would not be necessary to fully refuel it for the round trip to Luna. But let's take the most pessimistic guess and say Starship would have to
"put it to rest" (Score:2)
That guy Brandon Johnson is a hoot.
It's very strange how scientific theories have "enemies" who always try to suppress them. That's not how science works.
The Comet Research Group folks have an expedition to the same area going on this year and they're going to do their measurements and publish them. Maybe they're agree, maybe they won't. That's how science actually works, not scheming cabals.
The Younger Dryas impact theory has good explanatory value that competing theories do not. But it was never depen
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And it will be hilarious if the Comet Research Group finds out it was asteroids and not even a comet.
It was a roving black hole and nothing anyone says can convince me differently.
Nah (Score:2)
It's probably safe to put the Younger Dryas impact hypothesis back to rest for a while.
Probably not. A more probable impact location has long been considered on the Canadian glacier (since the entire area was a glacier at the time).
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I hate to sound like a weird conspiracy nut, but this Younger Dryas theory had always fascinated me. There seems to be SOME science behind it (the merits of which can be debated, of course). But the concept that humans have a longer history and civilization that was lost long ago is intriguing.
Not saying it was high tech, science fiction type civilization. The possibility exists of course of some level of advancement, but I doubt that. It's probably just humans getting an earlier start on civilization. But
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There seems to be SOME science behind [the Younger Dryas comoet impact hypothesis] (the merits of which can be debated, of course).
This hypothesis is supported by a lot of evidence now. There is a layer with space elements in the strata from around the world, dated to that time.
But the concept that humans have a longer history and civilization that was lost long ago is intriguing.
Ok, that's a little less supported lol.
Wrong summary about Younger Dryas (Score:2)
The Younger Drys was not a cooling period, quite the opposite.
It cooled down just before the Younger Dryas, and during the Younger Dryas it stayed cold on same level more or less, and at the end, we had a rapid rise in temperatures.
https://en.wikipedia.org/wiki/... [wikipedia.org]