Ten minutes difference, and Earth could still be Planet of the Dinosaurs

[Winston]

Ten minutes difference, and Earth could still be Planet of the Dinosaurs

https://www.3quarksdaily.com/3quark...tes-difference-that-doomed-the-dinosaurs.html

I changed the "would" to "could" in the title because I don't like what I believe to be the unjustified absolute certainty of the actual article title. Excerpt:

The asteroid is falling towards Earth on a fixed trajectory, but the Earth itself is spinning beneath it, one revolution every 24 hours. This corresponds to around 1,000 miles an hour in the region of interest. So arriving ten minutes earlier or later would have placed the impact some 150 miles further to the East or West. And if this had happened, the asteroid would have missed the shallow gypsum-rich continental shelf, and encountered only the oceans on either side. No gypsum in the impact zone, no sulphuric acid haze, no long deep winter. While things might have been pretty rough for anything living within a couple of thousand miles or so, the rest of the world would hardly have noticed.

 

[Woody's Workshop]

I will say this...
We can speculate about almost anything that "Could Have Been"...
Since there is no historic record of a massive water impact, we do simulations based upon assumptions.
So...what can be taken from speculation is un-absolute in fact.

 

[Peartree]

It's much less than that. Since the earth is traveling around the sun at 67,000 miles per hour, arriving ten minutes later would have meant that the earth was 11,000 miles away. Clean miss.

 

[Steven]

The Chicxulub Crater tends to lend evidence for the impact. https://en.wikipedia.org/wiki/Chicxulub_crater. I don't see this as blatant 'speculation' nor do I see it as irrefutable proof, but evidence nevertheless.

 

[Peartree]

The Chicxulub Crater tends to lend evidence for the impact. https://en.wikipedia.org/wiki/Chicxulub_crater. I don't see this as blatant 'speculation' nor do I see it as irrefutable proof, but evidence nevertheless.

I get what you're saying, but my reading of that particular comment wasn't that he doubted the impact, but simply that it was speculative to assume the results would have been substantively different if the impact had occurred well out into the Atlantic (or the Pacific) basin.

 

[Steven]

"Since there is no historic record of a massive water impact." I took it differently.

 

[Onebadhawk]

It's much less than that. Since the earth is traveling around the sun at 67,000 miles per hour, arriving ten minutes later would have meant that the earth was 11,000 miles away. Clean miss.

+1...

Teddy

 

[markkoelsch]

The object was huge moving very fast. An ocean would not slow it a lot before hitting ocean bottom.

 

[Steven]

The impact itself will depend on the ocean's level at the time too.

 

[Cl(VII)]

It's much less than that. Since the earth is traveling around the sun at 67,000 miles per hour, arriving ten minutes later would have meant that the earth was 11,000 miles away. Clean miss.

Yep. He is accounting for axial spin in his 10 minutes, but not orbital spin. He is using time as a sloppy measure of the point he is trying to make. I think the crux of the argument hangs on the presence of gypsum with it's high sulfur content at that location. Spewing all that sulfur into the air in all manner of oxidation states given the energy involved would have ultimately led to the formation of sulfuric acid droplets in the atmosphere which drove the extreme cooling experienced after the impact, and the subsequent mass extinction. Where as if the impact site were in an area of low crust sulfur there would have been less dramatic cooling due to the relative lack of (lower concentration of) sulfur spewed into the atmosphere by the impact.

Cool, I guess, geological observation regarding a major climatic/extinction event, but a really sloppy way of framing it. A decidedly Earth-centric way of looking at the collision of 2 bodies, i.e. ignoring the trajectory of the incoming body...his argument assumes it hits anyway.

 

[markkoelsch]

The impact itself will depend on the ocean's level at the time too.

If the object is several miles in diameter, made of sense rock or iron, moving 30-40000 mph the ocean depth is not going to make much of a difference- it would be through it a fraction of a second. It would hit the ocean floor with energy vey similar to what it was before hitting the ocean surface.

 

[Steven]

If the object is several miles in diameter, made of sense rock or iron, moving 30-40000 mph the ocean depth is not going to make much of a difference- it would be through it a fraction of a second. It would hit the ocean floor with energy vey similar to what it was before hitting the ocean surface.

Given a large enough size to the object and of course the level of the ocean would be less detrimental. As we also know, objects much smaller have caused less catastrophic consequences.

 

[MClark]

There are also the rocks that missed the earth and continued on without a trace. If earth had been 10 minutes late and the Dino killer missed it may of had a partner much larger hit.
There are so many chances for failure in the path that brought us here. If our ancestors coming out of Africa had turned left rather than right and were eaten by lions everything could be different.

 

[Steven]

There are also the rocks that missed the earth and continued on without a trace. If earth had been 10 minutes late and the Dino killer missed it may of had a partner much larger hit.
There are so many chances for failure in the path that brought us here. If our ancestors coming out of Africa had turned left rather than right and were eaten by lions everything could be different.

Pretty much. Just one single variable put in place or altogether removed and an entirely different outcome ensues. Just to name but one of perhaps countless examples are the near misses many of us have had with an auto accident alone. Much like an asteroid belt where they are perpetually colliding and missing each other.

 

[MClark]

The Great Game of Celestial Pinball

 

[shreadvector]

A Sound of Thunder

 

[markkoelsch]

https://impact.ese.ic.ac.uk/ImpactEffects/?_ga=2.63764591.1136663813.1502236303-84338220.1502236303

 

[Nytrunner]

The Great Game of Celestial Pinball

At risk of setting off the Alien Conspiracy crowd *duck*, That was either a fantastic shot or someone threw the planet into TILT.

 

[boatgeek]

Another fun one is the Tobe supervolcano (https://en.wikipedia.org/wiki/Toba_catastrophe_theory). Toba was the largest volcanic eruption in the geological record, and went up most recently around 70,000 years ago. It left 6" of ash over most of South Asia, and some researchers said it probably took 200 years to settle all of the ash out of the atmosphere. As with most things global-temperature related, the exact impact to global temperatures is controversial, but there's some evidence average temps dropped by 15 C for a couple of years, reducing the snow level by ~10,000 feet.

Genetic analysis of people around the world shows that **** sapiens was reduced to ~1,000-10,000 individuals at around the same time. Coincidence?

 

[Nytrunner]

I knew this thread title reminded me of something.

[video=youtube;ly9Qcboe4ow]https://www.youtube.com/watch?v=ly9Qcboe4ow[/video]


If I get banned for this....it was worth it!

 

[RIB]

Manus Domini Dei

manus Domini Dei

 

[markkoelsch]

Another fun one is the Tobe supervolcano (https://en.wikipedia.org/wiki/Toba_catastrophe_theory). Toba was the largest volcanic eruption in the geological record, and went up most recently around 70,000 years ago. It left 6" of ash over most of South Asia, and some researchers said it probably took 200 years to settle all of the ash out of the atmosphere. As with most things global-temperature related, the exact impact to global temperatures is controversial, but there's some evidence average temps dropped by 15 C for a couple of years, reducing the snow level by ~10,000 feet.

Genetic analysis of people around the world shows that **** sapiens was reduced to ~1,000-10,000 individuals at around the same time. Coincidence?

No coincidence at all. Super volcanoes are the most powerful thing on the planet. Toba could have easily eliminated us the last time, and when the next super volcano goes it could happen.

 

[Winston]

I get what you're saying, but my reading of that particular comment wasn't that he doubted the impact, but simply that it was speculative to assume the results would have been substantively different if the impact had occurred well out into the Atlantic (or the Pacific) basin.

Correct. However, on the Earth moving around the sun bit, my core assumption was the same as his - that the asteroid still hit the Earth in which case the Earth's rotation would be the only variable.

 

[Winston]

If the object is several miles in diameter, made of sense rock or iron, moving 30-40000 mph the ocean depth is not going to make much of a difference- it would be through it a fraction of a second. It would hit the ocean floor with energy vey similar to what it was before hitting the ocean surface.

Correct, but the author's claim related to what the ocean floor was composed of and how that would affect the ejecta to include gasses.

 

[Winston]

I will say this...
We can speculate about almost anything that "Could Have Been"...

The point is that there are so many events and conditions which could have so easily gone otherwise and we simply wouldn't be here. However, the fact that we ARE here is the result of so many things that DID go right. Otherwise, obviously, we wouldn't be here to marvel that they did:

The anthropic principle is a philosophical consideration that observations of the Universe must be compatible with the conscious and sapient life that observes it. As a result, it is unremarkable that this universe has fundamental constants [and the very local Earth and Solar System events - W], that happen to fall within the narrow range thought to be compatible with life.

That seems pretty damned obvious to me - if things weren't exactly as they are we wouldn't be here to wonder WHY they are.

That all leads to this with which I agree. However, once again, I would add the world "probably" in the title... but that doesn't sell books:

Rare Earth: Why Complex Life is Uncommon in the Universe

https://www.amazon.com/dp/0387952896/?tag=skimlinks_replacement-20

 

[Winston]

Aaaaaand another recent (21 Aug 2017) paper indicates that it didn't really matter much as where it hit because the soot from global fires would have prevented photosynthesis for two years anyway:

Dinosaur-killing Asteroid Could Have Caused 2 Years of Darkness

https://astrobiology.com/2017/08/di...id-could-have-caused-2-years-of-darkness.html

These new details about how the climate could have dramatically changed following the impact of a 10-kilometer-wide asteroid will be published Aug. 21 in the Proceedings of the National Academy of Sciences.

Scientists also calculate that the force of the impact would have launched vaporized rock high above Earth's surface, where it would have condensed into small particles known as spherules. As the spherules fell back to Earth, they would have been heated by friction to temperatures high enough to spark global fires and broil Earth's surface. A thin layer of spherules can be found worldwide in the geologic record.