[HN Gopher] Effect of a giant meteorite impact on Paleoarchean e...
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Effect of a giant meteorite impact on Paleoarchean environment and
life
Author : kristianp
Score : 130 points
Date : 2024-11-17 00:02 UTC (22 hours ago)
(HTM) web link (www.chemistryworld.com)
(TXT) w3m dump (www.chemistryworld.com)
| kevinkeller wrote:
| I love this type of articles where we can reconstruct what
| happened so long ago just based on careful observations.
|
| Some other instances I've come across:
|
| * The K-Pg extinction event that wiped off dinosaurs had the
| impact it did because the asteroid happened to impact a shallow
| water region. This kicked up a lot of sulfur (in gypsum) that
| further affected global climate:
| https://en.wikipedia.org/wiki/Chicxulub_crater#Effects
|
| * Earth likely had rings ~466M years ago. We deduced this by
| looking at impact craters from that time period, and seeing that
| they all lie near the equator (accounting for continental drift):
| https://www.sciencedirect.com/science/article/pii/S0012821X2...
|
| * Earth's rotation period was probably frozen at 21h, ~600M years
| ago, likely due to interaction between lunar and solar tides.
| This resonance could have been broken by ice ages (!!!). Amazing
| to think that global climate affects earth's rotation:
| https://en.wikipedia.org/wiki/Earth%27s_rotation#Resonant_st...
| thangalin wrote:
| > reconstruct what happened so long ago just based on careful
| observations.
|
| Me too! My book is filled with them. Like how minerals in lava,
| affected by Earth's magnetic field, lock into place while
| cooling, which provides us with yet another cross-check for
| radiometric dating. See page 23:
|
| https://impacts.to/downloads/lowres/impacts.pdf
| chiefalchemist wrote:
| Not to nitpick but the dinosaurs were on already on the way
| out, the asteroid merely finished them off early.
|
| https://www.theatlantic.com/magazine/archive/2018/09/dinosau...
| Arech wrote:
| To the best of my knowledge not everyone agrees to that
| hypothesis. One of the strongest arguments against it is that
| paleontological evidence is always incomplete. Holes in it
| that are treated in favor of the hypothesis are actually
| smaller or comparable to holes that appear just due to
| incompleteness.
| Timwi wrote:
| The dinosaurs were not "wiped off", by which I mean they are
| not extinct. This is an extremely widespread misconception that
| popular science articles like this one keep perpetuating. We
| should do better and help people understand that (some)
| dinosaurs survived and evolved into modern birds. Birds are
| dinosaurs. Dinosaurs are alive today.
| Qem wrote:
| When referring to dinosaurs, most people are thinking about
| non-avian, teethed dinosaurs anyway.
| asah wrote:
| https://www.google.com/search?q=bike+shedding
| datameta wrote:
| Here is the Chixculub impact effect in realtime simulated as
| happening in today's world:
| https://youtu.be/ya3w1bvaxaQ?si=S-jmFegMo63HKzID
| jeffbee wrote:
| The paper also mentions that, at the time, "dinosaur
| killer"-sized objects hit the Earth every 15 million years on
| average, which must have been sort of disruptive.
| kevinkeller wrote:
| Likely due to this:
| https://en.wikipedia.org/wiki/Late_Heavy_Bombardment
| jeffbee wrote:
| What these authors claimed recently was that prior LHB
| estimates were low by a large factor.
| https://www.nature.com/articles/s41561-021-00835-9
| kevinkeller wrote:
| Thanks for the paper link!
| 1970-01-01 wrote:
| Vote for Giant Meteor 2028!
|
| https://votegiantmeteor.com/
| hehehheh wrote:
| When is the next one coming? Or what is the probability
| distributuon like?
| patrickthebold wrote:
| It's a poisson distribution.
| dataflow wrote:
| Have the data actually been fit a Poisson distribution? Or is
| this is just a guess assuming constant rate and independence?
| glial wrote:
| No natural phenomena ever exactly fits any probability
| distribution.
| dataflow wrote:
| Right but I'm saying do we have data showing it's even
| close? (Genuinely asking, I have no idea.)
| Q_is_4_Quantum wrote:
| except the emission spectra from atoms :)
| nverno wrote:
| I imagine it is more of an exponential decay mixed with
| poisson since strikes were far more common back in the day.
| Also, I'd guess an exponential decay in the expected size of
| impactors over time as they've been smashing themselves into
| pieces.
| Arech wrote:
| Likely it isn't, because the Solar system today and 3Bln
| years ago are two very different systems.
| rad_gruchalski wrote:
| If things go sideways in 2029, the next one comes in 2036.
| dang wrote:
| The paper is at https://www.pnas.org/doi/10.1073/pnas.2408721121.
| We've adopted its title above.
| Timwi wrote:
| The article perpetuates the widespread misconception that
| dinosaurs are extinct. In reality, (some) dinosaurs survived and
| evolved into modern birds. Everything from penguins to ostriches,
| hummingbirds to albatrosses and woodpeckers to eagles is a
| dinosaur.
|
| Science communication should do better and clear up this
| misunderstanding.
|
| It would be so much cooler to say that the asteroid killed the
| _pterosaurs_. Not only is it factually correct, it also opens
| doors to more curiosity. Why do they say pterosaurs instead of
| dinosaurs? Turns out they are separate clades. The pterosaurs,
| plesiosaurs and mosasaurs are all extinct as best as we can tell.
| The dinosaurs are not.
| bregma wrote:
| Dinosaurs are delicious. They taste like chicken.
| pier25 wrote:
| Proof we live in a simulation. Everything tastes like
| chicken!
| jvanderbot wrote:
| This is fascinating. Although I'm having trouble mapping your
| comment onto this:
| https://opengeology.org/historicalgeology/case-studies/dinos...
|
| What is the complete set and which are extinct?
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