Controversial impact crater under Greenland’s ice is surprisingly ancient | Hacker News Reader

Controversial impact crater under Greenland’s ice is surprisingly ancient

science.org

93 pointsrbanffy25 comments

I'm consistently impressed and grateful that we live in times where we have the science to understand these relatively unimportant but very interesting facts about the world.

"Nearly 50 grains of sand collected from the same watershed, analyzed using the decay of radioactive potassium to argon, yielded about the same age"

I'm familiar with the science, and maybe I'm just easily impressed, but this sort of line always lightly blows my mind.

It is visible on Google Maps here https://www.google.co.uk/maps/place/78%C2%B043'28.6%22N+66%C...

Is this the cause of the Paleocene-Eocene Thermal Maximum? Even though it is too old to be tied to the Younger Dryas impact hypothesis it is still around the age attributed to a transition in geological epochs. The end of the Paleocene was marked by a mass extinction of 30-50% of species. During the following Eocene epoch, with presumably many empty niches, there were many new species that evolved.

The more we look, the more evidence we are finding that periodic mass extinctions are caused by cosmic impacts.

This begs the ancillary question - would faster cosmic impacts speed up or slow down evolution? There are surely habitable planets with impacts orders of magnitude more and less impacts.

I assume by faster you mean more frequent. When it comes to impacts faster just means more destructive. However, an increase in frequency of large impacts could cut off evolutionary pathways. For example, frequent impacts could make the land uninhabitable to most species.

Although the article says that particular strike didn't cause a temperature plunge, is it implying that an impact _can_ cause a temperature plunge?

Ridiculous thought that just came to my head, can our current climate problems be mitigated somehow with a well... precisioned... humanity-created impact or explosion? I wonder if some kooky people have considered this as a solution.

Yes definitely! A large impact can kick enough debris into the atmosphere to cool the earth. And people have floated the possibility of injecting basically a bunch of “debris” to combat global warming.

The problem is that the system is chaotic and injecting and then maintaining the exactly correct level of debris that cools us off a bit without triggering a global crop failure or runaway ice age is effectively impossible, not to mention the air quality issues intrinsic to basically all versions of this scenario.

Me naively thinks its better to ie put some nano foil which takes ie 5% of the light passing through on some stable orbit between earth and sun and have sun blocked without any further particulate pollution, which would end up falling on us while we breath it.

It has benefit that its position may degrade on its own over time, or be just moved when convenient. Still a gargantuan engineering project, possibly out of reach for current technology to do reliably.

It's completely doable, it just takes some multi-government commitment.

A fleet of solar sails would be the cheapest and fastest, for example, it can accomplish this with great redundancy, whilst being steerable and powered using the very sun they'll block.

The size of the sails would have to be huge, so a very interesting engineering problem to be solved.

Changing the Earth's albedo at the surface would be more controllable than pumping a bunch of particulate matter into the atmosphere. Probably a lot more expensive as well but the tradeoff is worth it since it would allow you to quickly undo it or modify it if things go badly.

High-albedo urban areas also generally need less power for cooling during warm weather.

That reminds me of a meme I can't find.

Scientists: We can block out the sun to prevent climate change!

Me: Is it going to rain tomorrow?

Scientists: The climate is a complicated system we can't just...

Me: Leave the fucking sun alone

The problem is not so much climate warming but climate change: the increase in temperature is not even and the consequences are much more dramatic than a mere +2C. Dry places become drier, wet places become wetter, windy places become winder and so on.

I would bet a big asteroid-like explosion would not be finely controlled and would cause unexpected changes too...

It's explained in great detail in this infomercial https://www.youtube.com/watch?v=0SYpUSjSgFg

https://en.wikipedia.org/wiki/Solar_geoengineering

https://en.wikipedia.org/wiki/Nuclear_winter

Anyone knows Randall Carlson's take on this ?

I've been listening to Randall's Kosmographia podcast Younger Dryas episodes. In the multiple episodes he lays out research supporting and detracting from the YD impact hypothesis. When they discuss the Hiawatha impact crater it is regarded as a possibility but not a sure thing with correlation to YD being reserved until more evidence is found. From what I have heard Randall is more of a credible independent scientist than he is given credit for. There is very little jumping to conclusions and always demanding evidence to support hypotheses.

He said, if it were 12000 years old, that would be a massive clue for the Hancock's theories. Well… it's a little bit older. Not what they hoped for.

>researchers say it occurred 58 million years ago

Only by a bit.

Hancock's an idiot but Randall at least seems to be nominally based in science.

I guess they finally found The Fortress of Solitude...

I’ve seen the Thing, just fuckin leave it there.

Pedantic but an impact crater either is or is not. Scientists (and others) might have controversial opinions, theories and hypothesis' about the crater and us mere mortals will be forced to take sides.

Controversial means "of, relating to, or arousing controversy [1]", it doesn't mean the existence is disputed.

E.g. a controversial drug, controversial news report, controversial rule.

[1]: https://www.merriam-webster.com/dictionary/controversial

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