Content of Earth-impacting meteors over time

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In summary, the conversation discusses the history of meteor impacts on Earth and the different types of meteorites, particularly the high percentage of chondrites found compared to nickel/iron ones. The speaker also mentions their own collection of meteorites, including examples of iron, ordinary chondrite, and pallasite meteorites. They also mention a recent find of a large pallasite in Kansas, USA.
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jim mcnamara
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http://www.nature.com/articles/s41550-016-0035
Rare meteorites common in the Ordovician period

About 466 million years ago, a large asteroid had a really bad day, and
fragments from the collision have dominated meteorites impacting the Earth
since that time.

Circa 1 billion years ago there was a similar event involving the asteroid Vesta
which dominated the fragments impacting Earth. Back then.

I guess you could call it: "meteor weather" on a huge time scale.

phys.org article:
https://phys.org/news/2017-01-big-picture-meteorites-giant-space-collision.html
 
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Hi @Jim

Somehow I missed this post you did, way back then :smile:

Interesting articles. I find it fascinating that most falls way back then were chondrites
of one type or another where the falls in the last say 100,000 yrs appear to be more nickel/iron
in composition, at least going by what has been seen to fall and by what has been found and identified.

My own collection the ratio would be ~ 70%/30% nickel/iron to what ever else ( chondrite etc).
This is not a personal preference towards Ni/Fe ones, to the contrary, I find the others are more
difficult to source. Yet Wiki etc state that ~ 87% of all meteorites found are in the chondrite class.

just some examples from my own collection...

Iron.

CLASS: Med Octahedrite, 111CD
Western Australia ( State), Australia
IMAG0835sm.jpg


Iron

CLASS: Iron, Fine octahedrite, IVA
Sweden
IMAG0847sm.jpg
Ordinary Chondrite
CLASS: Stone, Ordinary chondrite (H5)
Morocco reg., NW Africa
IMAG0845sm.jpg


Chondrite
complete fragment with fusion crust
CLASS: Stone, Ordinary chondrite (H5)
Mali
IMAG0853sm.jpg
and very new to the collection, I finally got a couple of Pallasites
Class: Pallasite (Stony Iron)
Kansas, USA

IMAG0833sm.jpg


for the above one ...

from Wiki
Notable pallasite finds[edit]
Although pallasites are a rare meteorite type, enough pallasite material is found in museums and meteorite collections and is available for research. This is due to large finds, some of which yielded more than a metric ton. The following are the largest finds:


Brenham, Kansas, United States. In 1890 the find of about 20 masses with a total weight of 1,000 kilograms (2,200 lb) around the shallow Haviland Crater were reported. More masses were found later, including one of 454 kilograms (1,001 lb) from a depth of 5 feet (1.5 m), the total amounting to about 4.3 tonnes (4.2 long tons; 4.7 short tons). A piece of 487 kilograms (1,074 lb) is in the Field Museum of Natural History, Chicago. In 2005, Steve Arnold of Arkansas, USA, and Phil Mani of Texas, USA, unearthed a large mass of 650 kilograms (1,430 lb) and in 2006 several new large masses [11][12]
Cheers
Dave
 
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What is the composition of Earth-impacting meteors over time?

The composition of Earth-impacting meteors can vary greatly and depends on the type of meteor. However, the most common elements found in these meteors are iron, nickel, and silicates.

How has the content of Earth-impacting meteors changed over time?

The content of Earth-impacting meteors has changed over time as the solar system has evolved. In the early stages, meteors were composed mostly of dust and gas. As the solar system aged, larger and more complex materials such as rocks and metals became more common in meteors.

Are there any patterns or trends in the content of Earth-impacting meteors?

Yes, there are patterns and trends in the content of Earth-impacting meteors. For example, there is a higher concentration of iron in meteors that have originated from the asteroid belt, while meteors from comets tend to have a higher percentage of water and other volatile compounds.

How does the size of a meteor impact its content?

The size of a meteor can impact its content in several ways. Larger meteors are more likely to have a diverse range of materials, including metals, silicates, and even organic compounds. Additionally, larger meteors are more likely to survive the atmospheric entry and impact, allowing for a better representation of their original composition.

Can studying the content of Earth-impacting meteors provide insight into the history of our solar system?

Yes, studying the content of Earth-impacting meteors can provide valuable insights into the history of our solar system. These meteors are considered "time capsules" that can contain materials dating back to the formation of the solar system. By analyzing their composition, scientists can better understand the processes and events that have shaped our solar system over billions of years.

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