O Meteorito de Sikhote-Alin atingiu a Rússia há 77 anos

A 1.7kg individual meteorite from the Sikhote Alin meteorite shower

  

An iron meteorite fell on the Sikhote-Alin Mountains, in southeastern Russia, in 1947. Large iron meteorite falls have been witnessed and fragments recovered but never before, in recorded history, a fall of this magnitude. An estimated 23 tonnes of fragments survived the fiery passage through the atmosphere and reached the Earth.

 

Orbit

Because the meteor fell during daytime, it was observed by many eyewitnesses. Evaluation of this observational data allowed V. G. Fesenkov, then chairman of the meteorite committee of the USSR Academy of Science, to estimate the meteoroid's orbit before it encountered the Earth. This orbit was ellipse-shaped, with its point of greatest distance from the sun situated within the asteroid belt, similar to many other small bodies crossing the orbit of the Earth. Such an orbit was probably created by collisions within the asteroid belt.  

 

Size

Sikhote-Alin is a massive fall with the pre-atmospheric mass of the meteoroid estimated at approximately 90,000 kg. A more recent estimate by Tsvetkov (and others) puts the mass at around 100,000 kg.

Krinov had estimated the post-atmospheric mass of the meteoroid at some 23,000 kg (51,000 lb). 

 

Strewn field and craters

The strewn field for this meteorite covered an elliptical area of about 1.3 km² (0.50 sq mi). Some of the fragments made impact craters, the largest of which was about 26 m (85 ft) across and 6 m (20 ft) deep. Fragments of the meteorite were also driven into the surrounding trees. 

 

Composition and classification

The Sikhote-Alin meteorite is classified as an iron meteorite belonging to the meteorite group IIAB and with a coarse octahedrite structure. It is composed of approximately 93% iron, 5.9% nickel, 0.42% cobalt, 0.46% phosphorus, and 0.28% sulfur, with trace amounts of germanium and iridium. Minerals present include taenite, plessite, troilite, chromite, kamacite, and schreibersite.

 

Specimens

Specimens of the Sikhote-Alin Meteorite are basically of two types:

1. individual, thumbprinted or regmaglypted specimens, showing fusion crust and signs of atmospheric ablation
2. shrapnel or fragmented specimens, sharp-edged pieces of torn metal showing evidence of violent fragmentation

The first type probably broke off the main object early in the descent. These pieces are characterized by regmaglypts (cavities resembling thumb prints) in the surface of each specimen. The second type are fragments which were either torn apart during the atmospheric explosions or blasted apart upon impact on the frozen ground. Most were probably the result of the explosion at 5.6 km (3.5 mi) altitude.

A large specimen is on display in Moscow. Many other specimens are held by Russian Academy of Science and many smaller specimens exist in the collectors' market.

 

 in Wikipédia

Na pré-história os humanos já conheciam o valor e a importância dos meteoritos...

O material de uma ponta de flecha da Idade da Pedra caiu do céu

 

 

 

O meteorito usado na criação da ponta de flecha terá caído na Estónia, tendo viajado mais de 1.600 quilómetros até chegar à Suíça.

Numa revelação extraordinária, uma equipa de arqueólogos descobriu que uma ponta de flecha da Idade do Bronze, escavada na Suíça no século XIX, foi feita com um meteorito, que pode ter tido origem na Estónia. O estudo foi publicado na Journal of Archaeological Science.

A ponta de seta também nos dá ideias sobre extensas redes de comércio que existiam há milhares de anos, que levaram o ferro da Estónia até à Suíça.

Esta descoberta foi feita durante uma procura detalhada por artefactos antigos de ferro meteorítico, liderada pelo geólogo Beda Hofmann do Museu de História Natural de Berna e da Universidade de Berna, na Suíça.

O ferro, particularmente o ferro puro, era uma mercadoria escassa nos tempos pré-históricos, o que obrigou os primeiros humanos a utilizar o recurso mais facilmente disponível - meteoritos de ferro.

Estes corpos celestes, geralmente compostos de ferro, níquel e vestígios de outros metais, terão sido a principal fonte de ferro para as ferramentas e armas da Idade do Bronze.

O que torna esta ponta de seta particularmente intrigante é a sua origem europeia. A maioria desses artefactos são normalmente encontrados no Médio Oriente, Egito e na Ásia, tornando as descobertas europeias muito raras.

A ponta de seta foi descoberta na povoação de Mörigen, que floresceu durante a Idade do Bronze, entre 800 e 900 a.C, revela o Science Alert.

Embora a povoação esteja a uma curta distância do campo Twannberg, repleto de fragmentos de ferro meteorítico de uma rocha que caiu do céu antes da última Idade do Gelo, a ponta de seta não corresponde ao ferro meteorítico do campo Twannberg.

Em vez disso, a sua composição corresponde a uma classe específica de meteorito de ferro, conhecida como meteoritos IAB.

Três grandes meteoritos IAB na Europa correspondem à composição da ponta de seta: Bohumilitz, da República Checa, Retuerte de Bullaque, de Espanha, e Kaalijarv da Estónia.

Os investigadores acreditam que Kaalijarv, que caiu na Terra por volta de 1.500 a.C. e espalhou fragmentos ideais para a criação de objetos pequenos e afiados, como pontas de seta, é a fonte mais provável.

Apesar da considerável distância de aproximadamente 1.600 quilómetros entre Mörigen e Kaalijarv, os autores sugerem que o ferro meteorítico viajou pelas mesmas rotas de comércio que o âmbar do Báltico.

 

in ZAP

O Meteorito de Sikhote-Alin caiu há 76 anos

A 1.7kg individual meteorite from the Sikhote Alin meteorite shower

  

An iron meteorite fell on the Sikhote-Alin Mountains, in southeastern Russia, in 1947. Large iron meteorite falls have been witnessed and fragments recovered but never before, in recorded history, a fall of this magnitude. An estimated 23 tonnes of fragments survived the fiery passage through the atmosphere and reached the Earth.

 

Orbit

Because the meteor fell during daytime, it was observed by many eyewitnesses. Evaluation of this observational data allowed V. G. Fesenkov, then chairman of the meteorite committee of the USSR Academy of Science, to estimate the meteoroid's orbit before it encountered the Earth. This orbit was ellipse-shaped, with its point of greatest distance from the sun situated within the asteroid belt, similar to many other small bodies crossing the orbit of the Earth. Such an orbit was probably created by collisions within the asteroid belt.  

 

Size

Sikhote-Alin is a massive fall with the pre-atmospheric mass of the meteoroid estimated at approximately 90,000 kg. A more recent estimate by Tsvetkov (and others) puts the mass at around 100,000 kg.

Krinov had estimated the post-atmospheric mass of the meteoroid at some 23,000 kg (51,000 lb). 

 

Strewn field and craters

The strewn field for this meteorite covered an elliptical area of about 1.3 km² (0.50 sq mi). Some of the fragments made impact craters, the largest of which was about 26 m (85 ft) across and 6 m (20 ft) deep. Fragments of the meteorite were also driven into the surrounding trees. 

 

Composition and classification

The Sikhote-Alin meteorite is classified as an iron meteorite belonging to the meteorite group IIAB and with a coarse octahedrite structure. It is composed of approximately 93% iron, 5.9% nickel, 0.42% cobalt, 0.46% phosphorus, and 0.28% sulfur, with trace amounts of germanium and iridium. Minerals present include taenite, plessite, troilite, chromite, kamacite, and schreibersite.

 

Specimens

Specimens of the Sikhote-Alin Meteorite are basically of two types:

1. individual, thumbprinted or regmaglypted specimens, showing fusion crust and signs of atmospheric ablation
2. shrapnel or fragmented specimens, sharp-edged pieces of torn metal showing evidence of violent fragmentation

The first type probably broke off the main object early in the descent. These pieces are characterized by regmaglypts (cavities resembling thumb prints) in the surface of each specimen. The second type are fragments which were either torn apart during the atmospheric explosions or blasted apart upon impact on the frozen ground. Most were probably the result of the explosion at 5.6 km (3.5 mi) altitude.

A large specimen is on display in Moscow. Many other specimens are held by Russian Academy of Science and many smaller specimens exist in the collectors' market.

 

 in Wikipédia

O Meteorito de Sikhote-Alin chegou caiu na Terra há 75 anos!

A 1.7kg individual meteorite from the Sikhote Alin meteorite shower (coasrsest octahedrite, class IIAB). This specimen is about 12cm wide. Sikhote Alin meteorite shower fell on 1947 February 12 in the dense forest of eastern Siberia, and over 23 tons of meteoritic material has been recovered.

  

An iron meteorite fell on the Sikhote-Alin Mountains, in southeastern Russia, in 1947. Large iron meteorite falls have been witnessed and fragments recovered but never before, in recorded history, a fall of this magnitude. An estimated 23 tonnes of fragments survived the fiery passage through the atmosphere and reached the Earth. 

    

The 10th anniversary stamp. It reproduces a painting by P. J. Medvedev.

  

Orbit

Because the meteor fell during daytime, it was observed by many eyewitnesses. Evaluation of this observational data allowed V. G. Fesenkov, then chairman of the meteorite committee of the USSR Academy of Science, to estimate the meteoroid's orbit before it encountered the Earth. This orbit was ellipse-shaped, with its point of greatest distance from the sun situated within the asteroid belt, similar to many other small bodies crossing the orbit of the Earth. Such an orbit was probably created by collisions within the asteroid belt.  

 

Size

Sikhote-Alin is a massive fall with the pre-atmospheric mass of the meteoroid estimated at approximately 90,000 kg. A more recent estimate by Tsvetkov (and others) puts the mass at around 100,000 kg.

Krinov had estimated the post-atmospheric mass of the meteoroid at some 23,000 kg (51,000 lb). 

 

Strewn field and craters

The strewn field for this meteorite covered an elliptical area of about 1.3 km² (0.50 sq mi). Some of the fragments made impact craters, the largest of which was about 26 m (85 ft) across and 6 m (20 ft) deep. Fragments of the meteorite were also driven into the surrounding trees. 

 

Composition and classification

The Sikhote-Alin meteorite is classified as an iron meteorite belonging to the meteorite group IIAB and with a coarse octahedrite structure. It is composed of approximately 93% iron, 5.9% nickel, 0.42% cobalt, 0.46% phosphorus, and 0.28% sulfur, with trace amounts of germanium and iridium. Minerals present include taenite, plessite, troilite, chromite, kamacite, and schreibersite.

 

Specimens

Specimens of the Sikhote-Alin Meteorite are basically of two types:

1. individual, thumbprinted or regmaglypted specimens, showing fusion crust and signs of atmospheric ablation
2. shrapnel or fragmented specimens, sharp-edged pieces of torn metal showing evidence of violent fragmentation

The first type probably broke off the main object early in the descent. These pieces are characterized by regmaglypts (cavities resembling thumb prints) in the surface of each specimen. The second type are fragments which were either torn apart during the atmospheric explosions or blasted apart upon impact on the frozen ground. Most were probably the result of the explosion at 5.6 km (3.5 mi) altitude.

A large specimen is on display in Moscow. Many other specimens are held by Russian Academy of Science and many smaller specimens exist in the collectors' market. 

 

Section

 

Thumbprinted individual

   

 in Wikipédia

O Meteorito de Sikhote-Alin chegou ao nosso planeta há 74 anos

A 1.7kg individual meteorite from the Sikhote Alin meteorite shower (coasrsest octahedrite, class IIAB). This specimen is about 12cm wide. Sikhote Alin meteorite shower fell on 1947 February 12 in the dense forest of eastern Siberia, and over 23 tons of meteoritic material has been recovered.

  

An iron meteorite fell on the Sikhote-Alin Mountains, in southeastern Russia, in 1947. Large iron meteorite falls have been witnessed and fragments recovered but never before, in recorded history, a fall of this magnitude. An estimated 23 tonnes of fragments survived the fiery passage through the atmosphere and reached the Earth. 

    

The 10th anniversary stamp. It reproduces a painting by P. J. Medvedev.

  

Orbit

Because the meteor fell during daytime, it was observed by many eyewitnesses. Evaluation of this observational data allowed V. G. Fesenkov, then chairman of the meteorite committee of the USSR Academy of Science, to estimate the meteoroid's orbit before it encountered the Earth. This orbit was ellipse-shaped, with its point of greatest distance from the sun situated within the asteroid belt, similar to many other small bodies crossing the orbit of the Earth. Such an orbit was probably created by collisions within the asteroid belt.  

 

Size

Sikhote-Alin is a massive fall with the pre-atmospheric mass of the meteoroid estimated at approximately 90,000 kg. A more recent estimate by Tsvetkov (and others) puts the mass at around 100,000 kg.

Krinov had estimated the post-atmospheric mass of the meteoroid at some 23,000 kg (51,000 lb). 

 

Strewn field and craters

The strewn field for this meteorite covered an elliptical area of about 1.3 km² (0.50 sq mi). Some of the fragments made impact craters, the largest of which was about 26 m (85 ft) across and 6 m (20 ft) deep. Fragments of the meteorite were also driven into the surrounding trees. 

 

Composition and classification

The Sikhote-Alin meteorite is classified as an iron meteorite belonging to the meteorite group IIAB and with a coarse octahedrite structure. It is composed of approximately 93% iron, 5.9% nickel, 0.42% cobalt, 0.46% phosphorus, and 0.28% sulfur, with trace amounts of germanium and iridium. Minerals present include taenite, plessite, troilite, chromite, kamacite, and schreibersite.

 

Specimens

Specimens of the Sikhote-Alin Meteorite are basically of two types:

1. individual, thumbprinted or regmaglypted specimens, showing fusion crust and signs of atmospheric ablation
2. shrapnel or fragmented specimens, sharp-edged pieces of torn metal showing evidence of violent fragmentation

The first type probably broke off the main object early in the descent. These pieces are characterized by regmaglypts (cavities resembling thumb prints) in the surface of each specimen. The second type are fragments which were either torn apart during the atmospheric explosions or blasted apart upon impact on the frozen ground. Most were probably the result of the explosion at 5.6 km (3.5 mi) altitude.

A large specimen is on display in Moscow. Many other specimens are held by Russian Academy of Science and many smaller specimens exist in the collectors' market. 

 

Section

 

Thumbprinted individual

   

 in Wikipédia

Pedra usada como calço era, afinal, um meteorito de 100 mil dólares

Uma professora da Universidade do Michigan, nos EUA, descobriu que uma pedra usada como calço nos últimos 30 anos era, na realidade, um meteorito que poderá valer cerca de 100 mil dólares.

De acordo com o Huffington Post, Mona Sirbescu, professora de Geologia da Universidade do Michigan, nos EUA, conta que, quando viu a pedra pela primeira vez, percebeu logo que “havia ali alguma coisa especial”.

“É o espécime mais valioso que já vi na minha vida, monetária e cientificamente”, disse Sirbescu num comunicado divulgado pela universidade.

A pedra, que afinal era um meteorito, pertencia a um homem de Grand Rapids, no Michigan, que preferiu manter o anonimato, que a levou à docente para ser examinada durante este ano.

Geralmente, a professora tem muitos destes pedidos, no entanto, “há 18 anos que a resposta é categoricamente ‘não'”, disse, citada na mesma nota.

O norte-americano contou à professora que tinha aquela pedra desde 1988, quando comprou uma quinta em Edmore, também no Michigan. O antigo dono dessa propriedade contou-lhe que era um meteorito que ele e o seu pai tinham avistado nos anos 30.

O homem contou a Sirbescu que ficou com a pedra nos 30 anos seguintes, mesmo depois de se ter mudado daquela quinta, e que a usava como calço ou para fazer apresentações na escola dos filhos.

Recentemente, o homem começou a ler histórias de pessoas que encontravam e vendiam pedaços de meteoritos, o que o levou a tentar confirmar a origem daquela rocha e se valeria alguma coisa, conta a universidade.

Trata-se de um meteorito com aproximadamente 88% de ferro e 12% de níquel, uma  avaliação depois validada por Catherine Corrigan, geóloga do Instituto Smithsonian, em Washigton.

O dono do meteorito, avaliado em cerca de 100 mil dólares, está a pensar vendê-lo a um museu ou colecionador, e já prometeu que vai doar 10% da receita à universidade.

in ZAP