No gypsum in the impact zone, no sulphuric acid haze
August 7, 2017 10:21 AM   Subscribe

If the asteroid that killed the dinosaurs had showed up ten minutes earlier or later, there would have been no mass extinction.
posted by Chrysostom (23 comments total) 30 users marked this as a favorite
 
Neat! Is this a widely accepted conclusion, or just a hypothesis for now?
posted by radicalawyer at 10:36 AM on August 7, 2017 [1 favorite]


Neat! This kind of thing is always fun to think about. (Also, if they ever do another season of Futurama, this could make for a pretty good time travel episode.)
posted by Atom Eyes at 10:38 AM on August 7, 2017


Ah, that's cool! I didn't know about the gypsum connection.
posted by Secretariat at 10:43 AM on August 7, 2017


Link is dead, any mirror?
posted by Wretch729 at 10:46 AM on August 7, 2017


This was a fascinating article, thanks for posting!
posted by lemonade at 10:55 AM on August 7, 2017


In ten minutes the Earth would have moved 11,000 miles in its orbit… meaning that the asteroid would have missed it entirely. (Albeit an extremely close pass).
posted by Bora Horza Gobuchul at 11:00 AM on August 7, 2017 [13 favorites]


Bora Horza Gobuchul is correct, I don't know where this 10 minutes comes from. The earth is about 13k kilometers across, and moves at 20 kilometers / minute relative to the sun. So more like 40 seconds and it would have missed entirely. Asteroids are not, to my knowledge, synced to the orbit of the earth. This is also the reason why asteroid defense plans nearly always call for a "temporal miss". Instead of trying to deflect the orbit to one side, you try to slow down the asteroid enough that it simply intersects the earth's orbit after the earth has passed through. Space is really, really, mindbogglingly big, to steal part of a line from Douglas Adams.
posted by wnissen at 11:28 AM on August 7, 2017 [10 favorites]


In ten minutes the Earth would have moved 11,000 miles in its orbit...

This is why if they ever invent a time machine I will not volunteer to be the first person to take it on a test drive.
posted by Atom Eyes at 11:34 AM on August 7, 2017 [9 favorites]


The article explains where the "10 minutes" comes from: they're considering what would have happened if the asteroid had arrived slightly earlier or later, but along the same trajectory relative to the earth's center. Seems pretty reasonable to me.
posted by teraflop at 11:39 AM on August 7, 2017 [8 favorites]


If the asteroid that killed the dinosaurs had showed up ten minutes earlier or later, there would have been no mass extinction.

And therefore God.
posted by Billiken at 12:01 PM on August 7, 2017


And therefore God.

Indeed. Without this extinction event, there would likely have been no humans to cook up God. So, God, in His self-interest, timed the asteroid perfectly so that in the future there would be humans to create Him.
posted by busted_crayons at 12:42 PM on August 7, 2017 [5 favorites]


but along the same trajectory relative to the earth's center.

Well, then why not keep the trajectory the same relative to the Yucatan, if you're just fudging everything willy-nilly?

Also, isn't continental drift a thing? Was the Atlantic really asteroid-absorbingly deep 65 million years ago, or just a shallow sea?
posted by Sys Rq at 1:02 PM on August 7, 2017


For the smart-asses arguing about orbital velocity. The "10 minutes" line is actually trying to get at the idea that if the asteroid had hit 150 miles east or west of where it did, it would have missed the gypsum deposit, and its effect on the atmosphere (and thus on solar radiation reaching the Earth's surface) would have been dramatically lessened.
posted by agentofselection at 1:49 PM on August 7, 2017 [4 favorites]


If it helps, don't think of as ten minutes earlier/later sidereal time, think of it as ten minutes off by local time, corresponding to an infinitesimal change in the Earth's rotational velocity at some point in the earlier past, accumulating up to a ten minute differential by impact time.

(While my first thought was, yes, "Ten minutes later means it misses, so what's the point?" I got where they were going with it and find it still a nice way of thinking about it.)

I've occasionally run into this formulation for alternate histories before--mainly, I remember one suggesting the Tunguska meteor impacting at different points along the same latitude and how drastically different history could have been if it had hit at just about St. Petersburg.
posted by Four Ds at 2:26 PM on August 7, 2017 [4 favorites]


It is a lot less ambiguous to phrase it in terms of impact location than in terms of impact time, but then you miss out on the TED/clickbait formulation of "10 minutes would have saved the dinosaurs".
posted by Pyry at 2:37 PM on August 7, 2017 [4 favorites]


That was a beautifully written article.

And thinking about stuff like this is why I favor the position that intelligent alien life is incredibly rare. Life in the sense of animals and plants may be more common, but sentient life that can build spaceships may be limited to very small numbers of species that are widely separated in time. In our own example of one, look how easy it would have been for dinosaurs to continue to dominate until the present day. On this planet that is perfectly suited for the development of sentient life, it took the intervention of an asteroid appearing at just the right time or it wouldn't have happened.
posted by Kevin Street at 3:15 PM on August 7, 2017 [2 favorites]


Ah, I get it. It's not that the meteor itself could have been 10 minutes behind, but that the rotation of the earth could have been! It does say that, in a roundabout way (no pun intended), and the rotation of the earth is gradually slowing, so it's not out of the question that if it were a bit slower, the impact could have been otherwise.
posted by wnissen at 3:41 PM on August 7, 2017 [1 favorite]


The version of this story Radiolab tells has the falling molten glass roasting pretty much everything above ground, all around the world, everything dead in just a few hours.

Even if the heat burned just one hemisphere or just one continent, even if there were no sulphuric haze, wouldn't there be evolutionary opportunities for small burrowing mammals that survived inside the burn zone?

Maybe I just like the idea of a dinosaur ranch.
posted by Western Infidels at 3:53 PM on August 7, 2017 [1 favorite]


A++++ will click again

Fascinating, thanks.
posted by medusa at 5:46 PM on August 7, 2017


Indeed. Without this extinction event, there would likely have been no humans to cook up God. So, God, in His self-interest, timed the asteroid perfectly so that in the future there would be humans to create Him.

Or the god of mammals got the upper hand over the god of the dinosaurs.
posted by Laotic at 10:59 PM on August 7, 2017


Dinosaur God: "Hey, what's with this meteor fly-by you put on the schedule?"
Mammal God: "Oh, nothing to worry about, it'll miss by ten minutes..."
posted by tobascodagama at 8:31 AM on August 8, 2017 [2 favorites]


The version of this story Radiolab tells has the falling molten glass roasting pretty much everything above ground, all around the world, everything dead in just a few hours.

I know that's the current theory, but I still have my doubts about the sterilization being worldwide. Because, birds. A number of species survived K-T, and there's no evidence they were burrowing birds that I know of. The lizard/snake/mammal type survivors, even if there's not specific evidence for a survivor species living underground it's an extremely common characteristic in the family. Birds that build or use underground burrows are pretty rare, both now and as far as I know historically. If all the species that survived were burrowers, you'd expect it to be a foundational characteristic of the line, something that they then radiated away from.

There's a lot of hollow-nesting birds, but the kind of temperatures they are talking about, and the duration, a tree isn't going to save you. You have to be down in the temperature-stabilizing earth to do it, or immersed in water.

Of course, I'm not a paleontologist, so there may be more recent evidence I don't know about.
posted by tavella at 10:24 AM on August 8, 2017 [2 favorites]


The article seems to posit that the immediate and catastrophic heating effect was limited to 1000-1500 miles around the impact site. The cooling and acid rain effects shut down the food chain over the remainder of the globe over a slightly longer time period. (weeks-months probably, to go completely global, including in the southern hemisphere)
posted by wierdo at 10:05 PM on August 8, 2017 [1 favorite]


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