Iron meteorite. Origin of meteorites

Meteorites, super category of finds with a metal detector. Expensive and replenished regularly. The only problem is how to distinguish a meteorite... Finds that look like a stone and give a response from a metal detector are not uncommon on detecting. At first, he tried to rub it against the blade of a shovel, and over time, he collected in his head the characteristic differences between celestial meteorites and earthly shmurdyak.

How to distinguish a meteorite from an artifact of terrestrial origin. Plus photos from the forum of search engines, finds of meteorites and similar ones.

The good news is that 5000-6000 kilograms of meteorites fall on the earth in 24 hours. It is a pity that most of them go under water, but there are enough of them in the ground.

How to distinguish a meteorite

Two important properties. A meteorite never has an internal horizontal structure (layers). The meteorite does not look like a river stone.

Melted surface. If there is, that's a good sign. But if the meteorite lay in the ground or on the surface, the surface may lose its glaze (by the way, it is most often thin 1-2 mm).

Form. A meteorite can have any shape, even square. But if it's a regular ball or sphere, it's most likely not a meteorite.

magnetize. Almost all meteorites (about 90%) stick to any magnet. But the earth is full of natural stones with the same properties. If you see that it is metal, and it does not stick to a magnet, this find is most likely of terrestrial origin.

Appearance. Meteorites in 99% do not have inclusions of quartz and there are no "bubbles" in them. But often there is a grain structure. A good sign is "plastic dents", something like fingerprints in plasticine (the scientific name for such a surface is Regmaglipty). Meteorites most often contain iron, which, once on the ground, begins to oxidize, it looks like a rusty stone))

Photos of finds

There are a lot of photos of meteorites on the Internet ... I'm only interested in those that were found with a metal detector by ordinary people. Found and doubt whether it is a meteorite or not. Forum thread (bourgeois).

The usual expert advice is something like this ... Pay attention to the surface of this stone - the surface will definitely have dents. A real meteorite flies through the atmosphere, while it heats up very much and its surface “boils”. The upper layers of meteorites always retain traces of high temperature. Characteristic dents, similar to bursting bubbles, are the first characteristic feature of a meteorite.

You can try the stone for magnetic properties. Simply put, bring a magnet to it and move it over it. Find out if the magnet sticks to your stone. If the magnet sticks, then there is a suspicion that you really became the owner of a piece of a real celestial body. This type of meteorites is called iron. It happens that the meteorite does not magnetize too strongly, only in some fragments. Then it's probably a stony-iron meteorite.

There is also a type of meteorites - stone. It is possible to detect them, but it is difficult to determine that this is a meteorite. Here you can not do without chemical analysis. A feature of meteorites is the presence of rare earth metals. And it also has melting bark on it. Therefore, the meteorite is usually very dark in color. But there are also white ones.

Debris lying on the surface is not considered subsurface. You are not breaking any laws. The only thing that may sometimes be required is to obtain the opinion of the Committee on Meteorites of the Academy of Sciences, they must conduct research, assign a class to the meteorite. But this is if the find is very impressive, and it is difficult to sell it without a conclusion.

At the same time, it is impossible to argue that the search and sale of meteorites is an insanely profitable business. Meteorites are not bread, queues do not line up behind them. You can sell a piece of the "heavenly wanderer" more profitably abroad.

There are certain rules for the export of meteorite material. First you need to write an application to the Protection of Culture. There you will be sent to an expert who will write a conclusion whether the stone is subject to export. Usually, if it is a registered meteorite, there are no problems. You pay a state duty - 5-10% of the cost of the meteorite. And forward to foreign collectors.

Nine signs of a real extraterrestrial alien

To know how to spot a meteorite, you first need to know the types of meteorite. There are three main types of meteorites: stony meteorites, iron meteorites and stony iron meteorites. As the name implies, stony-iron meteorites usually consist of a 50/50 mixture of iron and silicate minerals. This is a very rare type of meteorites, it makes up about 1-5% of all meteorites. Identifying such meteorites can be very difficult. They resemble a metal sponge, in the pores of which there is a silicate substance. There are no rocks on Earth similar in structure to stony-iron meteorites. Iron meteorites make up about 5% of all known meteorites. It is a monolithic piece of an alloy of iron and nickel. Stony meteorites (ordinary chondrites) make up the majority, 80% to 95% of all meteorites that fall to earth. They are called chondrites because of the small spherical mineral inclusions called chondrules. These minerals are formed in a vacuum environment with zero gravity space, so they always have the shape of a sphere. Signs of a meteorite It is clear that the iron meteorite is the easiest to identify, and the stone one is the most difficult. Only a highly qualified specialist will be able to recognize for sure a stone meteorite. However, even a simple person can understand that in front of him is an alien from outer space by the simplest signs of a meteorite:

1. Meteorites are heavier than terrestrial stones. This is due to the greater density that meteorites have in comparison with terrestrial rocks.

2. 2. The presence of smoothed depressions, similar to finger dents on plasticine or clay - the so-called regmaglipts. These grooves, ridges, dippers, and depressions on the surface of a meteorite are formed in a process called ablation. This happens the moment a meteoroid passes through our atmosphere. At very high temperatures, less dense layers from the surface of the stone begin to melt, and this creates rounded depressions.

3. Sometimes the meteorite has an oriented shape and resembles a projectile head.

4. If the meteorite fell not too long ago, then there will most likely be a melting crust on its surface - a dark thin shell about 1 mm thick. As a rule, this dark black melt crust is very similar on the outside to coal, but if the meteorite is a stone type, then it usually has a light interior that looks just like concrete.

5. The fracture of the meteorite is often gray, sometimes small balls are visible on it, about 1 mm in size - chondrules.

6. In almost all celestial wanderers, inclusions of metallic iron can be seen on the polished section.

7. Meteorites are magnetized, and the compass needle near them deviates.

8. Over time, the meteorite changes its color, which becomes brown, rusty. This is caused by an oxidation reaction.

9. In meteorites that belong to the iron class, on a polished and acid-etched section, one can often see large metal crystals - Widmanstätten figures.

stone meteorites

Stony meteorites belong to the most heterogeneous class. It has absorbed all types of meteorites and their groups, which have one common feature: they are mostly stones, i.e. consist of silicate sand, which is different from other rock-forming minerals. However, stony meteorites are often so high in nickel and iron that they can be safely considered stony iron or atypical iron meteorites. However, due to the similarity in composition, these "outsiders" are currently usually referred to as stony meteorites.

As for the frequency of occurrence, stony meteorites account for 92.8% of all observed cases. So far, only about 35 tons of stone meteorites have been found, which is about 16% of the total mass of known meteorites. The reason for this is that usually stony meteorites are smaller than iron or stony-iron ones. Another reason is that stony meteorites are not easy to recognize, since they are very similar to terrestrial rocks and differ little from them in weight. In addition, due to their mineral composition, they weather much faster than their metallic counterparts, so old meteorites are found much less frequently.

Scientists divide stony meteorites into two main classes - chondrites And achondrites. Chondrites are the most common, accounting for 85.7% of known cases. At first glance, they are distinguished by the presence of spherical chondrules, inherent only in meteorites. Achondrites do not have chondrules, as their name implies, and are much rarer - they account for 7.1% of known cases.

At first glance, such a distinction seems arbitrary and superficial, like most of the categories of the old meteoritics, but modern research has shown that it is these classes that allow us to learn a lot about the origin of the solar system and therefore are distinguished correctly. In particular, it is currently known that chondrites represent almost unchanged primary cosmic matter, a witness to the emergence of the solar system, while achondrites reflect various stages of differentiation and/or development of cosmic matter. Achondrites are witnesses to how complex worlds, often very similar to our Earth, arose from primary chondrite matter due to impact, conglomeration and other geological processes, and open up a completely new picture of our own planet.

In this regard, the old distinction between iron, stony-iron and stony meteorites appears in a new light. If chondrites are more or less undifferentiated primary cosmic matter, then all other meteorites not only reflect different stages of differentiation, but also come from certain layers of differentiated parent bodies. Iron meteorites are samples of the core, iron-stony - soil, and stone meteorites of the achondrite class - the outer crust of other, geologically developed celestial bodies.

The Chelyabinsk meteorite is an ordinary chondrite, which contains metallic iron, olivine and sulfites, and a melting crust is also present. Received the name Chebarkul.

The meteorite raised from the bottom of Lake Chebarkul will be examined and then transferred for storage to the Chelyabinsk Regional Museum of Local Lore. The lifting of the celestial body from the water will be carried out by the Aleut company from Yekaterinburg. The divers managed to calculate the coordinates of the place where the meteorite is located and its approximate dimensions. A meteorite measuring 50x90 centimeters is located at a depth of nine meters.

The Chelyabinsk meteorite is a chondrite. Carbonaceous chondrites are "loose" meteorites of a silicate composition that is part of the core of ice comets. The Tunguska meteorite was just such a comet - a giant ball of dirty ice with dust and stones. The destruction of a celestial body over Nevada and California in 2012, the Chelyabinsk meteorite, are phenomena of the same order.

“The Chelyabinsk meteorite became an almost complete copy of the Tunguska meteorite and largely explained its phenomenon to scientists,” said Vitaly Romeiko, Moscow astronomer, head of the Zvenigorod observatory, leader of 24 Tunguska expeditions. - The analogy is direct. And here and there the explosion occurred several kilometers above the surface of the Earth. Both celestial bodies flew at the same time of day - early in the morning. Both of them ended up in the same geographical region - in Siberia. The whole complex of atmospheric phenomena - the flight of a superbolide, the glow of which was brighter than the sun, the white condensation trail in the sky, the hissing, crackling that accompanied the fall - the description of the explosion is very similar.

Kunashak is a stone meteorite-chondrite with a total weight of 200 kg (about 20 fragments) that fell on July 11, 1949 on the territory of the Kunashaksky district of the Chelyabinsk region. It was named after the village of Kunashak, the district center of the Chelyabinsk region, near which it was found.

Pervomaisky meteorite.
A chondrite meteorite weighing 49,000 grams fell on December 26, 1933 in the Yuryev-Polsky district of the Ivanovo region, in Pervomaisky village. “According to eyewitnesses, at six o’clock in the evening on December 26, 1933, a huge, moon-sized, utterly dazzling fireball with lightning speed swept through the sky from the southeast to the northwest almost through the entire Ivanovo region, scattered behind the Yuryev-Polsky fireworks cascade sparks and went out, breaking out for tens of kilometers around with thunderous peals and a long-lasting rumble. Glass rang, huts shuddered, panic seized the population ... "L.A. Kulik, 1934

Part of the Mill Sutter meteorite weighing 17.7 grams.
"A bright east-west moving fireball was seen on April 22, 2012 in California and Nevada at 7:51 am local daylight saving time. Mill Sutter is an unusual type of carbonaceous chondrite.

Chinese tektite, 1905 Tektites are formed as a result of the melting of the earth's crust during a powerful impact of a meteorite, and then scatter from the crater over long distances.

Stone meteorite Pultusk, type - Chondrite H5. Weight 11 gr.
The fall occurred on January 30, 1868 at 7:00 pm near the town of Pultusk, about 60 kilometers northeast of Warsaw. Thousands of people witnessed the fall of a large fireball, followed by a detonation and a "shower" of small debris falling on ice, land and houses over an area of ​​​​about 127 square kilometers. The estimated number of fragments was 68,780.
The total mass of meteorites is 8863 kg. The vast majority of fragments were small, (a few grams), now known as Pultusk peas.

Stone meteorite Gujba, a plate of the rarest meteorite weighing 41.39 grams.
The Gujba meteorite is a carbonaceous chondrite, bencubbinite type. A meteorite weighing about 100 kg was broken by local residents.
Fall: April 3, 1984 Yobe, Nigeria

The Ellersley meteorite hit the roof of a house in South Auckland in May 2004. It was chipped from falling on the iron roof.

Antarctic meteorite.
Thin section of crystalline chondrite with olivine-orthopyroxene content

Plainview meteorite. Stone meteorite that fell in 1917 in Texas

Plainview meteorite

Kirbyville (Eucrite) meteorite fell in Texas, USA, on November 12, 1906. The total mass is 97.7 g. It is an achondrite.

Portales Valley, Roosevelt County, New Mexico, USA Fall: 1998 Jun 13 7:30 AM MDT
Ordinary chondritis (H6). During the fall, explosions were heard and a smoky streak was visible in the sky.

Middlesbrough meteorite, England. Fell March 14, 1881. Weight 1.5 kg.
The meteorite belongs to the category of chondrites. Its age is approximately 4500 million years
3D scanning of the object was carried out by NASA specialists in 2010.

Pasamonte Fall year: 1933, USA Weight: 5.1 kg Achondrite

H5 Dar Bou Nali South Morocco

Chondrite. Italy, 1910

Carbonate chondrite

GaoGuenie Meteorite

Characteristics of the mineral.

Stone and iron bodies that fell to Earth from interplanetary space are called meteorites, and the science that studies them is called meteoritics. A variety of meteoroids (cosmic fragments of large asteroids and comets) move in near-Earth outer space. Their speeds range from 11 to 72 km/s. It often happens that the paths of their movement intersect with the Earth's orbit and they fly into its atmosphere. In some cases, a large meteoroid during its movement in the atmosphere does not have time to evaporate and reaches the Earth's surface. When hitting the ground, a meteorite can crumble into dust, or it can leave fragments. This remnant of a meteor (celestial) body is called a meteorite. During the year, about 2000 meteorites fall on the territory of Russia, for example.

All meteorites are considered scientific property and the exclusive property of the state on whose territory they fell (regardless of who exactly found the meteorite) - these are international norms. No citizen has the right to own meteorites, buy or sell them.

Rutile on hematite. Saint Gotthard, Switzerland (possible

Meteorite "Seymchan" (sawed off). Photo: A.A. Evseev.

Rutile on hematite. Mwinilunga, Zambia (possible
meteorite pseudomorphosis). 3x3 cm. Photo: A.A. Evseev.

Rutile on hematite over ilmenite. Mwinilunga, Zambia
(possible pseudomorphosis after a meteorite). Photo: A.A. Evseev.

Depending on the chemical composition, meteorites are divided into stony, iron and stony-iron meteorites. Iron and stony-iron meteorites are almost entirely composed of nickel iron. They fall out about 20% of the total. It is very easy to find a recently fallen stone meteorite, since a noticeable crater forms around the place of impact, and iron ones cannot be distinguished from ordinary stones, since their surface is often completely melted and acquires a grayish or brownish color. Therefore, iron and stony-iron meteorites are found very rarely (due to the lack of metal detectors among the population). Everyone knows the so-called "hot stones from the sky", in 25% of cases they turn out to be iron-stone meteorites, for example, a metal detector reacts to them with a slight delay, after passing over them. Iron meteorites have a very clear response from a metal detector.

The best place to search for meteorites is the smooth steppe - 45% of all finds are made here. If you live in a different climate zone, you can go searching in the field (37% of all finds). Forest glades and river banks are not very suitable for these purposes. A good place to search are the channels of mountain rivers, lined with rounded stones.

Meteorites are found much less frequently than tektites. To check if you have found an iron meteorite, this can be done in a simple way: iron meteorites on a chip usually shine like iron or like nickel. If you find a stone-iron meteorite, then scattered small shiny particles of a silvery-white color are visible on the break. These are nickel iron inclusions. Among these particles there are golden sparkles - inclusions of a mineral consisting of iron in combination with sulfur (pyrite). There are meteorites, which are like an iron sponge, in the voids of which are grains of a yellowish-green color of the mineral olivine (garnet, formed at the site of a meteorite falling and hitting the ground, a frequent companion of diamonds in diamond pipes). In the photo above - a crater from a meteorite fall in Uzbekistan. The photo below shows various iron and stone meteorites stored as exhibits in mineralogical museums or even in the open.

If a celestial body does not reach the earth and burns up completely in the atmosphere, it is called a fireball or meteor. The meteor draws a bright trail, the fireball seems to burn with fire in flight. They do not leave any traces on the surface of the earth; accordingly, a huge number of celestial bodies burn out in the Earth's atmosphere every year. It is completely useless to look for their traces on the ground at the place of the alleged fall, even if the fireball or meteor traced a very bright and noticeable trace in the sky at night. Fireballs and meteors that burn up in the atmosphere during the day are not visible in sunlight. Cosmic bodies, which consist mainly of dry ice, also evaporate in the atmosphere, although they fly, leaving a very noticeable and bright trail in the dark.