Scientists explained where the magnetic field of meteorites comes from

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Summarize this content to 100 words One of the striking features of iron meteorites is that they are often magnetic. Their magnetism is not strong, but still carries information about their origin. This is why astronomers do not recommend that meteorite hunters use magnets to distinguish meteorites from ordinary rock, as magnets can erase a meteorite’s magnetic history, which has important scientific value.Magnetic meteorites occur because they form in the presence of a magnetic field. The iron particles in the meteorite line up along the external magnetic field, which gives the meteorite its magnetism. For example, the Martian meteorite known as Black Beauty acquired its magnetism thanks to the strong magnetic field of young Mars.Some magnetic meteorites were apparently not supposed to form in a strong magnetic field. Iron meteorites are usually classified by chemical composition, such as the ratio of nickel to iron. One type, known as IVA, is fragments of small asteroids. Small asteroids do not have a strong magnetic field, so IVA meteorites should not be magnetic, but many of them are. A new study shows just how possible.Small asteroids are formed from a pile of debris. Small pieces of iron-rich rock eventually accumulate, turning into an asteroid. In order for a body to be able to generate a strong magnetic field, it is necessary to have liquid iron to create a dynamo effect, and since there is no such effect on small asteroids, they cannot have a magnetic field either. Is it possible?Asteroids also experience collisions over time. It is as a result of these collisions that fragments break off from them, turning into meteorites that we find on Earth. But the authors show that collisions can create a magnetic dynamo inside the asteroid. If the colliding bodies are not large enough to break up the asteroid, but large enough to melt a layer of material near the surface, then the following chain of events can occur.When the cold core of debris is surrounded by a molten layer of rock, it heats up. Light elements evaporate from the core and migrate to the surface, which leads to the mixing of layers and the occurrence of convection. Convection of iron creates a magnetic field that is imprinted on parts of the asteroid. In the next collision, magnetic debris is formed, some of which reaches the Earth.Thus, the magnetism of IVA meteorites is not due to the initial formation of their parent asteroid, but to later collisions that set their core in motion. Knowing this, researchers can better understand the history of our solar system and how phenomena such as planetary drift could have caused more frequent asteroid collisions.

Scientists explained where the magnetic field of meteorites comes from

One of the striking features of iron meteorites is that they are often magnetic. Their magnetism is not strong, but still carries information about their origin. This is why astronomers do not recommend that meteorite hunters use magnets to distinguish meteorites from ordinary rock, as magnets can erase a meteorite’s magnetic history, which has important scientific value.

Magnetic meteorites occur because they form in the presence of a magnetic field. The iron particles in the meteorite line up along the external magnetic field, which gives the meteorite its magnetism. For example, the Martian meteorite known as Black Beauty acquired its magnetism thanks to the strong magnetic field of young Mars.

Some magnetic meteorites were apparently not supposed to form in a strong magnetic field. Iron meteorites are usually classified by chemical composition, such as the ratio of nickel to iron. One type, known as IVA, is fragments of small asteroids. Small asteroids do not have a strong magnetic field, so IVA meteorites should not be magnetic, but many of them are. A new study shows just how possible.

Small asteroids are formed from a pile of debris. Small pieces of iron-rich rock eventually accumulate, turning into an asteroid. In order for a body to be able to generate a strong magnetic field, it is necessary to have liquid iron to create a dynamo effect, and since there is no such effect on small asteroids, they cannot have a magnetic field either. Is it possible?

Asteroids also experience collisions over time. It is as a result of these collisions that fragments break off from them, turning into meteorites that we find on Earth. But the authors show that collisions can create a magnetic dynamo inside the asteroid. If the colliding bodies are not large enough to break up the asteroid, but large enough to melt a layer of material near the surface, then the following chain of events can occur.

When the cold core of debris is surrounded by a molten layer of rock, it heats up. Light elements evaporate from the core and migrate to the surface, which leads to the mixing of layers and the occurrence of convection. Convection of iron creates a magnetic field that is imprinted on parts of the asteroid. In the next collision, magnetic debris is formed, some of which reaches the Earth.

Thus, the magnetism of IVA meteorites is not due to the initial formation of their parent asteroid, but to later collisions that set their core in motion. Knowing this, researchers can better understand the history of our solar system and how phenomena such as planetary drift could have caused more frequent asteroid collisions.

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