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Out of curiosity, when did the asteroid extinction theory cement as the scientific consensus? I seem to recall that in my childhood (1980s, Canadian elementary

Out of curiosity, when did the asteroid extinction theory cement as the scientific consensus? I seem to recall that in my childhood (1980s, Canadian elementary schools) it was still treated as only one of several competing explanations, but now it’s pretty much an accepted fact. Which makes sense given all the evidence, but I still have this odd sensation making me feel like I missed the memo! Am I the only one who feels this way?

rrdharan 6y ago
Answering my own question: https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_e... So I guess it was indeed proposed around the time I was born and “proven” by the time I had outgrown dinosaurs as an interest/hobby...
- JohnJamesRambo 6y ago
  > With the exception of some ectothermic species such as the sea turtles and crocodilians, no tetrapods weighing more than 25 kilograms (55 pounds) survived.[5] I wish we could unite and start forming a plan to survive the next one. I wonder what that would entail?
  - EamonnMR 6y ago
    Detect it early enough and we can nudge it out of our way with a large rocket. Problems include: solar system is big, comets have really long orbital periods, we need to be good enough at predicting the path to be sure that the nudge is putting it in a good orbit we like and not setting us up for disaster. We do look for asteroids with the impression that if they ever found one coming out way we'd do a mission to stop it (though I don't think that's a real commitment.) See: https://en.m.wikipedia.org/wiki/Asteroid_impact_avoidance https://en.m.wikipedia.org/wiki/Asteroid_impact_avoidance
    - dogsgobork 6y ago
      The dinosaurs really messed up by not having a space program.
      - darkerside 6y ago
        If they really wanted to survive, they should have prioritized colonization of Mars over their silly interspecies zero sum resources-based conflicts.
        EamonnMR 6y ago
        If you can survive mars you can survive asteroid scoured earth.
      - mrexroad 6y ago
        Well, there a is a theory that dinosaurs evolved into a transwarp capable species, now residing over in the delta quadrant... [0] https://memory-alpha.fandom.com/wiki/Voth https://memory-alpha.fandom.com/wiki/Voth
    - plank_time 6y ago
      Oumuamua wasn’t detected until after it passed by the Earth so it’s a hard challenge to detect from far away.
      - eloff 6y ago
        I believe it came a close as 0.16 AU (tracing the path backward), which is 66 times further than the moon. Being an interstellar object though, it moves faster than the escape velocity to the sun, so it would pack a higher energy per unit of mass than a regular comet or asteroid. Fortunately such objects are also somewhat rare.
      - AnimalMuppet 6y ago
        OK, crazy idea time. Couldn't we detect such things with radar? Given the right frequencies, rocks and dirt will reflect - that's how terrain-following radar works. So yes, I think we could, but there are some significant problems. 1. 1/r^2 power loss, in both directions. We would need a massive radiator, and very sensitive detectors. 2. The detectors are in the wrong place. You send out your signal, and several hours later the response comes back, by which time the earth has rotated. So where your detector has to be depends on the distance to the object, but you don't know the distance to the object! So we'd need a bunch of detectors at various points around the globe. And we'd need a huge power source. Which brings me to solar flares. They emit radio waves. Do they emit enough power at the right frequencies to be useful for this?
  - gameswithgo 6y ago
    more telescopes and more rockets!
  - Symmetry 6y ago
    Well, these guys are working on getting humanity through smaller but similar events through feeding people despite years without any crop growth. https://allfed.info/ https://allfed.info/ We've actually got a fairly decent handle on asteroid protection right now with the cataloging work that's been done in the last couple of decades. Comet impacts, supervolcanos, and possibly a nuclear winter are really the biggest threats of this sort
  - totalZero 6y ago
    NASA told Congress in 2007 that we can nuke asteroids before they get too close. [0] In the impulsive category, the use of a nuclear device was found to be the most effective means to deflect a PHO [Potentially Hazardous Object]. Because of the large amount of energy delivered, nuclear devices would require the least amount of detailed information about the threatening object, reducing the need for detailed characterization. While detonation of a nuclear device on or below the surface of a threatening object was found to be 10-100 times more efficient than detonating a nuclear device above the surface, the standoff detonation would be less likely to fragment the target. A nuclear standoff mission could be designed knowing only the orbit and approximate mass of the threat, and missions could be carried out incrementally to reach the required amount of deflection. [0]https://www.nasa.gov/pdf/171331main_NEO_report_march07.pdf https://www.nasa.gov/pdf/171331main_NEO_report_march07.pdf
  - sliken 6y ago
    In simple terms a good space program. More sensors, more tracking objects, and the ability to get mass anywhere in the solar system to give an object a small nudge well ahead of impact. Neil deGrasse Tyson has made many similar comments, one quote “Dinosaurs are extinct today because they lacked opposable thumbs and the brainpower to build a space program.”
  - rorykoehler 6y ago
    There won’t be a next one. Not for us at least. We’re destroying our habitat to the point that we won’t be able to survive. Something better suited to the environment we’re creating will take our place.
- ip26 6y ago
  This part in particular: https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event#2016_Chicxulub_crater_drilling_project https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_e... I think was around when consensus shifted from "Yeah this is probably what happened" to "This is it"
  - tim333 6y ago
    I'm curious if the Deccan Traps, (https://en.wikipedia.org/wiki/Deccan_Traps https://en.wikipedia.org/wiki/Deccan_Traps) formed at about the same time on the opposite side of the planet were also caused by the asteroid. Not a standard theory but it makes sense to me that an asteroid hitting one side of the globe could cause shockwaves that crack the crust on the other.
- deleted 6y ago
  [deleted]
- jacobolus 6y ago
  Check out this 2-year-old New Yorker article, https://www.newyorker.com/magazine/2019/04/08/the-day-the-dinosaurs-died https://www.newyorker.com/magazine/2019/04/08/the-day-the-di...
scolson 6y ago
The Chicxulub crater off the top of the Yucatan peninsula is attributed for that particular event. It wasn't really known until the early/mid 90s I don't think.
- ghaff 6y ago
  Right. Although even after the discoveries related to the K-t boundary and the crater, there was a school of thought that it was just a contributing factor to a pre-existing general decline. My understanding is that there's now a general consensus that it was much more of a singular cataclysmic event.
  - jjk166 6y ago
    There's still a substantial group that thinks the impact was part of a 1-2 punch with the eruptions of the deccan traps, which produced a far larger impact on the atmosphere but over a longer period of time. Iridium from the asteroid impact is found in the basalt deposited by the deccan traps, so they definitely happened concurrently. That said, if you look at the patterns of extinction, survivors seem limited to things that could hide in burrows or in deep water and then survive for an extended period exclusively on scavenging, as if everything that happened to be on the surface was suddenly killed and then photosynthesis stopped working for a few years. Notably, species that would normally be very sensitive to climate change like small amphibians survive whereas generalists capable of long distance migration die out. There may have been ecological stress beforehand but a singular cataclysmic event turned it into a mass extinction.
    - tremon 6y ago
      so they definitely happened concurrently Do we know for sure that the volcanism in the Deccan traps wasn't caused/triggered by the asteroid impact? I know they're pretty much located at the opposite ends of the world, so could the shockwaves from the initial impact have created an amplified node at the other side? (edit: wikipedia[0] says it's inconclusive: > Although the Deccan Traps began erupting well before the impact, [..] the impact may have caused an increase in permeability that allowed magma to reach the surface and produced the most voluminous flows, accounting for around 70% of the volume [0] https://en.wikipedia.org/wiki/Deccan_traps#Chicxulub_crater https://en.wikipedia.org/wiki/Deccan_traps#Chicxulub_crater )
chiefalchemist 6y ago
I don't know. A couple of years ago I read a piece in (I believe) The Atlantic that proposed it was a massive volcanic eruption that did the dinos in. The sub-plot of the article was how science gets attached to an idea (i.e., it was an asteroid) and more or less self-fulfills that idea despite plenty of evidence that calls it into question. Found it! https://www.theatlantic.com/magazine/archive/2018/09/dinosaur-extinction-debate/565769/ https://www.theatlantic.com/magazine/archive/2018/09/dinosau...
plank_time 6y ago
The idea that we can know with any degree of certainty that an event tens of millions of years ago was the single cause of dinosaur extinction is absurd. It’s bad science. Case in point, a pandemic could have wiped out all the dinosaurs 1 million years before the asteroid hit and we would have no fossil evidence of that. The asteroid theory is still just a theory and for anyone to be arrogant enough to say that it is fact doesn’t deserve to teach science in any capacity.
- Jabbles 6y ago
  Adding in additional events that we have no evidence for would also be bad science. https://en.wikipedia.org/wiki/Extinction_event#Other_hypotheses https://en.wikipedia.org/wiki/Extinction_event#Other_hypothe...
  - plank_time 6y ago
    I’m not saying that they were killed by a pandemic. It’s an example of something that could happen that would never be detected by fossil evidence. There are potentially dozens of conceivable events that could have caused extinction level events and taking a single theory and selling it as fact is wrong. We should be teaching it as a theory with pretty decent evidence but not much more than that because it’s impossible to say what really happened. Anything more than “this is a plausible idea with some pretty good evidence behind it” is science fiction, not science.
    - Jabbles 6y ago
      This seems to be a much more reasonable stance, though just because you can conceive of something doesn't mean it should be taken seriously. Your previous comment included questionable phrases such as "any degree of certainty", "absurd", "just a theory".
      - plank_time 6y ago
        My point is that we are talking about an event that happened 70 million years ago. Think about how long ago that was. The amount of evidence that is leftover after 70 million years of time passing is infinitesimally minute. To think we can come to any conclusion with the tiny amounts of evidence that remains or to clue together all the remaining bits and pieces of residual evidence is extremely arrogant. It makes for a decent story and hypothesis, and it sounds plausible. But to teach people that this is basically fact is absurd, which is my point. It should be taught as a theory.

rrdharan 6y ago

Answering my own question: https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_e... So I guess it was indeed proposed around the time I was born and “proven” by the time I had outgrown dinosaurs as an interest/hobby...

JohnJamesRambo 6y ago
> With the exception of some ectothermic species such as the sea turtles and crocodilians, no tetrapods weighing more than 25 kilograms (55 pounds) survived.[5] I wish we could unite and start forming a plan to survive the next one. I wonder what that would entail?
- EamonnMR 6y ago
  Detect it early enough and we can nudge it out of our way with a large rocket. Problems include: solar system is big, comets have really long orbital periods, we need to be good enough at predicting the path to be sure that the nudge is putting it in a good orbit we like and not setting us up for disaster. We do look for asteroids with the impression that if they ever found one coming out way we'd do a mission to stop it (though I don't think that's a real commitment.) See: https://en.m.wikipedia.org/wiki/Asteroid_impact_avoidance https://en.m.wikipedia.org/wiki/Asteroid_impact_avoidance
  - dogsgobork 6y ago
    The dinosaurs really messed up by not having a space program.
    - darkerside 6y ago
      If they really wanted to survive, they should have prioritized colonization of Mars over their silly interspecies zero sum resources-based conflicts.
      - EamonnMR 6y ago
        If you can survive mars you can survive asteroid scoured earth.
    - mrexroad 6y ago
      Well, there a is a theory that dinosaurs evolved into a transwarp capable species, now residing over in the delta quadrant... [0] https://memory-alpha.fandom.com/wiki/Voth https://memory-alpha.fandom.com/wiki/Voth
  - plank_time 6y ago
    Oumuamua wasn’t detected until after it passed by the Earth so it’s a hard challenge to detect from far away.
    - eloff 6y ago
      I believe it came a close as 0.16 AU (tracing the path backward), which is 66 times further than the moon. Being an interstellar object though, it moves faster than the escape velocity to the sun, so it would pack a higher energy per unit of mass than a regular comet or asteroid. Fortunately such objects are also somewhat rare.
    - AnimalMuppet 6y ago
      OK, crazy idea time. Couldn't we detect such things with radar? Given the right frequencies, rocks and dirt will reflect - that's how terrain-following radar works. So yes, I think we could, but there are some significant problems. 1. 1/r^2 power loss, in both directions. We would need a massive radiator, and very sensitive detectors. 2. The detectors are in the wrong place. You send out your signal, and several hours later the response comes back, by which time the earth has rotated. So where your detector has to be depends on the distance to the object, but you don't know the distance to the object! So we'd need a bunch of detectors at various points around the globe. And we'd need a huge power source. Which brings me to solar flares. They emit radio waves. Do they emit enough power at the right frequencies to be useful for this?
- gameswithgo 6y ago
  more telescopes and more rockets!
- Symmetry 6y ago
  Well, these guys are working on getting humanity through smaller but similar events through feeding people despite years without any crop growth. https://allfed.info/ https://allfed.info/ We've actually got a fairly decent handle on asteroid protection right now with the cataloging work that's been done in the last couple of decades. Comet impacts, supervolcanos, and possibly a nuclear winter are really the biggest threats of this sort
- totalZero 6y ago
  NASA told Congress in 2007 that we can nuke asteroids before they get too close. [0] In the impulsive category, the use of a nuclear device was found to be the most effective means to deflect a PHO [Potentially Hazardous Object]. Because of the large amount of energy delivered, nuclear devices would require the least amount of detailed information about the threatening object, reducing the need for detailed characterization. While detonation of a nuclear device on or below the surface of a threatening object was found to be 10-100 times more efficient than detonating a nuclear device above the surface, the standoff detonation would be less likely to fragment the target. A nuclear standoff mission could be designed knowing only the orbit and approximate mass of the threat, and missions could be carried out incrementally to reach the required amount of deflection. [0]https://www.nasa.gov/pdf/171331main_NEO_report_march07.pdf https://www.nasa.gov/pdf/171331main_NEO_report_march07.pdf
- sliken 6y ago
  In simple terms a good space program. More sensors, more tracking objects, and the ability to get mass anywhere in the solar system to give an object a small nudge well ahead of impact. Neil deGrasse Tyson has made many similar comments, one quote “Dinosaurs are extinct today because they lacked opposable thumbs and the brainpower to build a space program.”
- rorykoehler 6y ago
  There won’t be a next one. Not for us at least. We’re destroying our habitat to the point that we won’t be able to survive. Something better suited to the environment we’re creating will take our place.
ip26 6y ago
This part in particular: https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_extinction_event#2016_Chicxulub_crater_drilling_project https://en.wikipedia.org/wiki/Cretaceous%E2%80%93Paleogene_e... I think was around when consensus shifted from "Yeah this is probably what happened" to "This is it"
- tim333 6y ago
  I'm curious if the Deccan Traps, (https://en.wikipedia.org/wiki/Deccan_Traps https://en.wikipedia.org/wiki/Deccan_Traps) formed at about the same time on the opposite side of the planet were also caused by the asteroid. Not a standard theory but it makes sense to me that an asteroid hitting one side of the globe could cause shockwaves that crack the crust on the other.
deleted 6y ago
[deleted]
jacobolus 6y ago
Check out this 2-year-old New Yorker article, https://www.newyorker.com/magazine/2019/04/08/the-day-the-dinosaurs-died https://www.newyorker.com/magazine/2019/04/08/the-day-the-di...

scolson 6y ago

The Chicxulub crater off the top of the Yucatan peninsula is attributed for that particular event. It wasn't really known until the early/mid 90s I don't think.

ghaff 6y ago
Right. Although even after the discoveries related to the K-t boundary and the crater, there was a school of thought that it was just a contributing factor to a pre-existing general decline. My understanding is that there's now a general consensus that it was much more of a singular cataclysmic event.
- jjk166 6y ago
  There's still a substantial group that thinks the impact was part of a 1-2 punch with the eruptions of the deccan traps, which produced a far larger impact on the atmosphere but over a longer period of time. Iridium from the asteroid impact is found in the basalt deposited by the deccan traps, so they definitely happened concurrently. That said, if you look at the patterns of extinction, survivors seem limited to things that could hide in burrows or in deep water and then survive for an extended period exclusively on scavenging, as if everything that happened to be on the surface was suddenly killed and then photosynthesis stopped working for a few years. Notably, species that would normally be very sensitive to climate change like small amphibians survive whereas generalists capable of long distance migration die out. There may have been ecological stress beforehand but a singular cataclysmic event turned it into a mass extinction.
  - tremon 6y ago
    so they definitely happened concurrently Do we know for sure that the volcanism in the Deccan traps wasn't caused/triggered by the asteroid impact? I know they're pretty much located at the opposite ends of the world, so could the shockwaves from the initial impact have created an amplified node at the other side? (edit: wikipedia[0] says it's inconclusive: > Although the Deccan Traps began erupting well before the impact, [..] the impact may have caused an increase in permeability that allowed magma to reach the surface and produced the most voluminous flows, accounting for around 70% of the volume [0] https://en.wikipedia.org/wiki/Deccan_traps#Chicxulub_crater https://en.wikipedia.org/wiki/Deccan_traps#Chicxulub_crater )

chiefalchemist 6y ago

I don't know. A couple of years ago I read a piece in (I believe) The Atlantic that proposed it was a massive volcanic eruption that did the dinos in. The sub-plot of the article was how science gets attached to an idea (i.e., it was an asteroid) and more or less self-fulfills that idea despite plenty of evidence that calls it into question. Found it! https://www.theatlantic.com/magazine/archive/2018/09/dinosaur-extinction-debate/565769/ https://www.theatlantic.com/magazine/archive/2018/09/dinosau...

plank_time 6y ago

The idea that we can know with any degree of certainty that an event tens of millions of years ago was the single cause of dinosaur extinction is absurd. It’s bad science. Case in point, a pandemic could have wiped out all the dinosaurs 1 million years before the asteroid hit and we would have no fossil evidence of that. The asteroid theory is still just a theory and for anyone to be arrogant enough to say that it is fact doesn’t deserve to teach science in any capacity.

Jabbles 6y ago
Adding in additional events that we have no evidence for would also be bad science. https://en.wikipedia.org/wiki/Extinction_event#Other_hypotheses https://en.wikipedia.org/wiki/Extinction_event#Other_hypothe...
- plank_time 6y ago
  I’m not saying that they were killed by a pandemic. It’s an example of something that could happen that would never be detected by fossil evidence. There are potentially dozens of conceivable events that could have caused extinction level events and taking a single theory and selling it as fact is wrong. We should be teaching it as a theory with pretty decent evidence but not much more than that because it’s impossible to say what really happened. Anything more than “this is a plausible idea with some pretty good evidence behind it” is science fiction, not science.
  - Jabbles 6y ago
    This seems to be a much more reasonable stance, though just because you can conceive of something doesn't mean it should be taken seriously. Your previous comment included questionable phrases such as "any degree of certainty", "absurd", "just a theory".
    - plank_time 6y ago
      My point is that we are talking about an event that happened 70 million years ago. Think about how long ago that was. The amount of evidence that is leftover after 70 million years of time passing is infinitesimally minute. To think we can come to any conclusion with the tiny amounts of evidence that remains or to clue together all the remaining bits and pieces of residual evidence is extremely arrogant. It makes for a decent story and hypothesis, and it sounds plausible. But to teach people that this is basically fact is absurd, which is my point. It should be taught as a theory.