Rock that punched hole in New Jersey house confirmed to be 4.6 billion-year-old meteorite

Jan 31, 2023
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I can accept the statement, "it was clear that this was not an Earth rock", from the scientific analysis of its composition. But how can scientists "{confirm] the space rock to be about 4.56 billion years old"? There is no mention of how they "confirmed" it. From the information given, the statement sounds far fetched and speculative, not scientific.
 
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Jun 7, 2021
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I can accept the statement, "it was clear that this was not an Earth rock", from the scientific analysis of its composition. But how can scientists "{confirm] the space rock to be about 4.56 billion years old"? There is no mention of how they "confirmed" it. From the information given, the statement sounds far fetched and speculative, not scientific.
They probably checked the shipping label on the bottom for the tracing # (which would give them the time sent & location of the sender).
 
They date the meteorites by looking at varios ratios of isotopes of gasses contained within. Different isotopes decay at different rates. They can tell when the atoms were created in a supernova event. They had to then condense into dust and form rocks. The rock itself is younger than the dated age.
 
Post #3 is correct. "There is no mention of how they "confirmed" it."

I did not see how the 4.6 Gyr age was measured, nothing specific. Specific report like Uranium, Rubidium, Potassium-Argon, etc, and if different ages were found too. The cosmic ray exposure age(s) I did not find reported either.
 
billslugg, do you have the reference paper showing this and *repeated many times* dating? I would like to read that and see the isochron fits too, thanks.
I am sorry, I was remembering a list I was looking at but it may have been a different meteorite. Now, I cannot find any details on this one. Perhaps they are simply going by guesswork since all ordinary chondrites were formed at about the same time. Maybe why they say: "approximately".
 
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Apr 18, 2020
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I suspect they determined the age from seeing what kind of meteorite it is, and knowing that all meteorites of that type were formed at around the time that the solar system itself formed.

Now how they know that is a longer story.
 
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Sky & Telescope published their report on this meteorite.


"Also, the material that comprises meteor showers is typically the size of sand grains and friable. A big one might reach the size of a chocolate chip or pea. To date, not a single meteorite of the 71,688 classified and named meteorites has been shown to originate from a meteor shower. While it's possible we may have a few cometary meteorites in our collections, the vast majority are fragments from asteroids."

The report shows 71,688 meteorites in the inventory today to study, date, and explain. What bolide said in post #11, "Now how they know that is a longer story.", is very accurate :)