Iron meteorite. Origin of meteorites

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

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

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

How to distinguish a meteorite

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

Melted surface. If there is one, this is 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 is a regular ball or sphere, most likely it is not a meteorite.

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

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

Photos of finds

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

The usual advice from experts goes something like this... Pay attention to the surface of this stone - the surface will definitely have indentations. 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 burst bubbles, are the first characteristic feature of a meteorite.

You can test the stone for its 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 have actually become the owner of a piece of a real celestial body. This type of meteorite is called iron meteorite. It happens that a meteorite is not very magnetic, only in some fragments. Then it might be a stony-iron meteorite.

There is also a type of meteorite - stone. It is possible to detect them, but it is difficult to determine that it is a meteorite. Here one cannot do without chemical analysis. A special feature of meteorites is the presence of rare earth metals. And there is also a fusion bark on it. Therefore, the meteorite is usually very dark in color. But there are also whitish ones.

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

At the same time, it is impossible to say that the search and sale of meteorites is an incredibly profitable business. Meteorites are not bread, there are no queues for them. You can sell a piece of the “sky wanderer” abroad for a better profit.

There are certain rules for the removal of meteorite material. First you need to write an application to Okhrankultura. There you will be sent to an expert who will write a report on whether the stone can be removed. 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 identify a meteorite, you first need to know the types of meteorites. There are three main types of meteorites: stony meteorites, iron meteorites, and stony iron meteorites. As the name suggests, stony-iron meteorites are typically composed of a 50/50 mixture of iron and silicate minerals. This is a very rare type of meteorite, accounting for about 1-5% of all meteorites. Identifying such meteorites can be very difficult. They resemble a metal sponge with a silicate substance in its pores. There are no rocks on Earth similar in structure to stony-iron meteorites. Iron meteorites make up about 5% of all known meteorites. This 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 in zero-gravity space, so they always have the shape of a sphere. Signs of a meteorite It is clear that an iron meteorite is the easiest to identify, and a stone meteorite is the most difficult. Only a highly qualified specialist can recognize a stone meteorite for sure. However, even an ordinary person can understand that this is an alien from outer space by the simplest signs of a meteorite:

1. Meteorites are heavier than earthly rocks. This is caused by the greater density that meteorites have compared to terrestrial rocks.

2. 2. The presence of smoothed depressions, similar to finger indentations on plasticine or clay - the so-called regmaglypts. These are indentations, ridges, buckets, and depressions on the surface of a meteorite that are formed through a process called ablation. This happens at the moment when a meteoroid passes through our atmosphere. At very high temperatures, the less dense layers on the surface of the stone begin to melt, and this creates round, depressed depressions.

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

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

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

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

7. Meteorites are magnetized, and the compass needle next to them is deflected.

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

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

Stone meteorites

Stone meteorites belong to the most heterogeneous class. It includes all types of meteorites and their groups, which have one common feature: they are mainly stones, i.e. consist of silicate sand, which is different from other rock-forming minerals. However, stony meteorites often have such high nickel and iron contents that they can safely be considered stony iron or atypical iron meteorites. However, due to the similarity of composition, at present these “outsiders” are usually classified as stony meteorites.

In terms of frequency of occurrence, stony meteorites account for 92.8% of all observed cases. To date, only about 35 tons of stony 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 meteorites. Another reason is that stony meteorites are not easy to recognize because they are very similar to Earth rocks and differ little 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 sphere-like chondrules, characteristic only of meteorites. Achondrites do not have chondrules, as their name suggests, and are much less common, accounting for 7.1% of known cases.

At first glance, such a distinction seems arbitrary and superficial, like most of the categories of 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 highlighted correctly. In particular, it is now known that chondrites represent almost unchanged primordial cosmic matter, witnessing 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, emerged from primordial chondritic matter through impact, conglomeration and other geological processes, and open up to us a completely new picture of our own planet.

In this regard, the old distinction between iron, stony and stony meteorites appears in a new light. If chondrites represent more or less undifferentiated primary cosmic matter, then all other meteorites not only reflect various stages of differentiation, but also originate from certain layers of differentiated parent bodies. Iron meteorites are samples of the core, stony-iron meteorites are samples of the soil, and stony meteorites of the achondrite class are samples of 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. Divers managed to calculate the coordinates of the place where the meteorite is located and its approximate dimensions. The meteorite, measuring 50x90 centimeters, is located at a depth of nine meters.

The Chelyabinsk meteorite is a chondrite. Carbonaceous chondrites are “loose” meteorites of silicate composition, part of the core of icy 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. Zvenigorod Observatory, leader of 24 Tunguska expeditions. - The analogy is direct. In both cases, the explosion occurred several kilometers above the Earth’s surface. Both celestial bodies flew at the same time of day - early in the morning. Both of them ended up in the same geographical region - Siberia. The whole complex of atmospheric phenomena - the passage 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 picture of the explosion matches the description very well.

Kunashak is a stone chondrite meteorite with a total weight of 200 kg (about 20 fragments) that fell on July 11, 1949 in the Kunashaksky district of the Chelyabinsk region. It was named after the village of Kunashak, the regional 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 the Pervomaisky village. “According to eyewitnesses, at six o’clock in the evening on December 26, 1933, a huge, moon-sized, extremely dazzling fireball with lightning speed swept across the sky from southeast to northwest across almost the entire Ivanovo region, scattered behind the Yuryev-Polsky fireworks cascade sparks and went out, erupting for tens of kilometers around with thunderclaps and a long-lasting roar. Glass rattled, huts shook, panic seized the population...” L.A. Kulik, 1934

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

Chinese tektite, 1905 Tektites arise as a result of the melting of the earth's crust during a powerful meteorite impact, 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 Pułtusk, approximately 60 kilometers northeast of Warsaw. Thousands of people witnessed the impact of a large fireball followed by detonation and a shower of small debris falling onto ice, ground and houses over an area of ​​about 127 sq km. The estimated number of fragments was 68,780.
The total mass of the meteorites is 8863 kg. The vast majority of the fragments were small (a few grams), now known as Pultusk peas.

Gujba stone meteorite, a rare meteorite plate weighing 41.39 g.
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 Ellerslie meteorite fell onto 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

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

Portales Valley, Roosevelt County, New Mexico, USA Fall: 1998 June 13 7:30 MDT
Ordinary chondrite (H6). As it fell, explosions were heard and a streak of smoke was visible in the sky.

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

Pasamonte Year of fall: 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 meteorology. A variety of meteorites (cosmic fragments of large asteroids and comets) move in near-Earth space. Their speeds range from 11 to 72 km/s. It often happens that their paths of movement intersect with the Earth’s orbit and they fly into its atmosphere. In some cases, a large meteoroid body, while moving through the atmosphere, does not have time to evaporate and reaches the surface of the Earth. When a meteorite hits the ground, it can crumble into dust or leave fragments behind. This remnant of a meteoric (celestial) body is called a meteorite. Over the course of a year, about 2,000 meteorites fall on Russian territory.

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. St. Gotthard, Switzerland (possible

Meteorite "Seymchan" (cut down). 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 from the meteorite). Photo: A.A. Evseev.

Depending on the chemical composition, meteorites are divided into stone, iron and stony-iron meteorites. Iron and stony iron meteorites consist almost entirely of nickel iron. They fall out about 20% of the total. A recently fallen stone meteorite is very easy to find, since a noticeable crater is formed around the impact site, 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 iron-stone 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, then 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 mountain river beds lined with rounded stones.

Meteorites are found much less frequently than tektites. There is a simple way to check whether you have found an iron meteorite: iron meteorites usually shine like iron or nickel when chipped. If you find a stony-iron meteorite, scattered small shiny silver-white particles are visible on the fracture. These are inclusions of nickel iron. Among such particles there are golden sparkles - inclusions of a mineral consisting of iron combined with sulfur (pyrite). There are meteorites that look like an iron sponge, in the voids of which are contained grains of the yellowish-green mineral olivine (garnet, formed at the site of a meteorite falling and hitting the ground, a frequent companion of diamonds in diamond tubes). In the photo above is 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 air.

If a celestial body does not reach the ground and completely burns up in the atmosphere, it is called a fireball or meteor. The meteor traces a bright trail, the car seems to burn with fire in flight. Accordingly, they do not leave any traces on the surface of the earth; a huge number of celestial bodies burn up in the Earth’s atmosphere every year. It is completely useless to look for their traces on the ground at the site of the supposed fall, even if the fireball or meteor traced a very bright and noticeable trace in the sky at night. During the day, fireballs and meteors burning in the atmosphere are not visible in sunlight. Cosmic bodies, consisting mainly of dry ice, also evaporate in the atmosphere, although they fly, leaving a very noticeable and bright trail in the dark.