a bit late to worry about putting my hat on, then.
A massive asteroid broke apart within the inner Solar System and showered the Earth and Moon with up to fifty quadrillion kilograms of meteoroids, say a trio of Japanese scientists. That's approximately 30 to 60 times more cosmic material than the Chicxulub prang that thoroughly ruined the dinosaurs' day. The academics …
I dunno.. Cubic meters or yards I reckon.. Or whatever the Vogon constructor fleet order their base fill by. Hopefully NASA's keeping a sharp lookout for the Vogon dozer/backhaul crews.
Kinda neat though the way scientists ponder dirt via soil/sediment/ice cores to try and figure out if dust is man-made, or golden stardust.
This is where Reg units come to the fore, rather than gee-whizz quadrilllions, whatever the fuck they are.
It would bury Wales under a kilometer of rock, and no, there isn't that option, it is just informative.
(assumes density 2.5 ton/m3, a reasonable figure = 5 x 10^13 ton, 2 x 10^10 m2)
Considering it was just before one of the snowball earth episodes it seems likely the dust kicked up from the impact might have caused Global Cooling much like a nuclear winter would. Might have triggered a nascent phase change to Snowball program 3.
But dinnae fash yersel, volcanic activity and CO2 and methane production and weathering from LIFE probably got the earth out of that program which then got downgraded to Ice Ages. The climate modellers reckon we might have seen off another ice age with the agricultural revolution which chopped down mature forests, burnt the stumps etc Grew seasonal crops using ploughing & probably kept methane farting cows, pigs & geeps while burning wood for cooking and warmth.
It didn’t just take the industrial revolution to kickstart Global Warming, it just added a supercharger to the engine our farming ancestors started. I’m just 2 generations away from the farm gate. Grandfather was a younger son so not in line to inherit the lease, a grammar school boy who became an engineer leaving my Great Uncle to run the farm.
There's evidence for the Late Heavy Bombardment about 4 billion years ago so this is relatively recent. All of these theories suggest that occasionally the Oort cloud outside the solar system may be disrupted and result in some trash running around the inner planets. While it's interesting to see if the Lunar evidence supports this, it would be very interesting to get dates on impact craters on Mars, maybe that's what caused Mars to be the lifeless planet that we see today.
I would be shocked if there is ANY evidence cite which rules out Oort cloud activity in favor of an asteroid. "At the same time" in this context almost certainly means "+/= 10-20MY". Whether it was a single event, or an orbital alignment that caused numerous events over this period has got to be entirely speculative.
Not only erosion and volcanism can obscure craters; consider the dino-killing Chicxulub impact crater, buried under sedimentary rock. Also, most asteroid strikes on Earth will occur in oceans, and the ocean floor is vigorously recycled into the mantle via subduction. The average age of the ocean floor is only about one sixth the age of the Cryogenian, and none of the ocean floor is as old as old as the impacts discussed in this article. So evidence of bombardment from 800 million years ago would likely be indirect, such as layers of shocked quartz in sedimentary rock.
Incidentally, the current interpretation of Martian history has the red planet dry, frozen and (relatively) airless before the impacts described here ( https://en.wikipedia.org/wiki/Geological_history_of_Mars ). Researchers from Elon Musk's Mars colonists might look for a spike in crater ages around 800 million years ago.
50 quadrillion kg
What's that in picograms?
Ah, metric... You're doing it wrong.
After kilograms comes megagram (Mg) then gigagram (Gg), teragram (Tg), petagram (Pg), exagram (Eg), zettagram (Zg), yottagram (Yg).
If you're going to have a multiple of a common prefix you think people are more familiar with, you might as well stick with Imperial units. Doesn't 7873652220888600000000000 stone just sound better?
They think a bigger body broke up 800 million years ago, some of it hit the Earth/Moon, and some of it makes up the asteroid Ryugu. What on Ryugu is going to show that 800 million year age, versus the much older age when the rock it is made of was originally formed (presumably when the solar system itself was formed)
Weathering.. Sunlight, cosmic radiation etc all have effects on surface material that can be detected; underlying rock that hasn't been exposed at the surface won't have this. On larger more solid asteroids, crater counts may help, too, although on smaller ones that are little more than piles of small rocks flying in formation crater-counting isn't a useful option.
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