Key Features and Importance of Meteorites in Physics
A galaxy is a mysterious place for all of us. In space, many cosmic incidents occur constantly. Some of them are extremely unknown to us. Also, the scientist has found the reasons for many cosmic incidents by their research. Among these cosmic incidents, meteorites are a known object to us. Now, we are going to define meteorites and discuss some facts about meteorites. It is a solid piece of a cosmic object such as an asteroid, meteoroid, comet, etc. Meteorites originate in outer space and pass through the atmosphere of any planet or satellite. It is known as the falling star or shooting star on the earth.
Meteorite Meaning
The meaning of the word meteorite is a piece of rock landed on the earth from outer space. Almost all the meteorites are made of rock. Some other meteorites are made of iron or nickel. The meteorites fall on the planets as a part of an asteroid, meteoroid, or comet. In space, these cosmic objects break into small parts by various cosmic reactions. The small parts survive in space and pass through the atmosphere of the planet and satellites. When the meteorite passes through the atmosphere of a planet or a satellite, it faces some factors such as pressure, weather, friction, chemical interactions with gases. As a result, it heats up and radiates energy. Finally, when it falls on a planet, it becomes a fireball. On the earth, these fireballs are known as falling stars.
Formation of Meteorites
There are many cosmic reactions and incidents ongoing in space constantly. The formation of meteorites is one of them. The source of meteorites are comets, meteoroids, asteroids, etc. These cosmic objects always wander around space. While wandering, they collide with other cosmic objects and break into small parts. Also, these cosmic objects can be broken by some cosmic reactions. The small pieces of the main objects somehow survive in space and become meteorites. The meteorites often pass through the atmosphere of planets and satellites. They face many reactions and forces in the atmosphere. If the gravitational energy of any planet or satellite becomes greater than the meteorite, it falls on its surface. The meteorite falls there as hot pieces of rock.
[Image will be uploaded soon]
Types of Meteorites
Depending on the material of the meteorites, they are classified into three types- iron meteorites, stony meteorites, and stony-iron meteorites. Iron meteorites are made of mainly iron, nickel, and minerals. It also contains a little amount of carbide and sulfide minerals. Most of the meteorites are stony meteorites with silicate minerals. Stony meteorites are of two types – chondrites, and achondrites. Chondrites are made from older cosmic objects of the solar system. Achondrites are made from the materials of the asteroids, the moon, mars, etc. Both types have different types of composition. Stony-iron meteorites include some amount of iron-nickel and silicate minerals in the composition. It is of two types- pallasites, and mesosiderites. Pallasites have big and beautiful olive-green crystals, which are made of magnesium-iron silicate, mesosiderites contain different types of rock, minerals, and metals in their composition.
Meteorite Impacts
When the meteorites pass through the atmosphere, they face some frictions and reactions. They come into the atmosphere of any planet or satellite and fall on their surface. For the frictions and reactions, the meteorite heats up and falls as hot pieces of rock. Small size meteorites don’t affect anything on the planet or satellite. If the size of the meteorites is big, it can make a hole on the surface and also can affect the surroundings by heat.
Meteorite Use
The meteorites contain stardust during formation. From the stardust, we can know about star formation and evolution. The stardust gives an idea about the formation of stars. From the structure of the meteorites, we can have an idea about the age and composition of the solar system. Also, meteorites give information about the geological history of planets and satellites, the evolution of the solar system, the history of life, etc.
Facts About Meteorites
Now, we are going to discuss some interesting facts about meteorites.
Each day millions of meteorites pass through the atmosphere of the earth.
Around 500 meteorites should reach the surface of the earth every year.
During the collision of a meteorite with the atmosphere, it is vaporized and leaves a trail called the meteor.
If so many meteors appear in the sky at the same time, it is called the meteor shower.
The meteor shower occurs for the cross of the orbit of the earth and comet.
FAQs on What is a Meteorite?
1. What is the difference between a meteoroid, a meteor, and a meteorite?
These terms describe three stages of the same object. A meteoroid is a small rock or piece of debris travelling through outer space. When a meteoroid enters Earth's atmosphere, it heats up and glows, creating a streak of light called a meteor, or shooting star. If any part of that object survives the journey and lands on Earth's surface, it is then called a meteorite.
2. What are meteorites made of, and what are their main types?
Meteorites are primarily composed of rock and metal, originating from asteroids or comets. They are classified into three main types based on their composition:
- Stony Meteorites: The most common type, mainly composed of silicate minerals, similar to rocks found on Earth.
- Iron Meteorites: Made almost entirely of an iron-nickel alloy, making them much denser than typical Earth rocks.
- Stony-Iron Meteorites: A rare type containing a roughly equal mix of silicate minerals and iron-nickel metal.
3. What is the scientific importance of studying meteorites?
Studying meteorites is crucial as they are some of the oldest objects in our solar system. They act as celestial fossils, providing direct evidence about the conditions and materials present during the formation of the Sun and planets. By analysing their chemical and isotopic composition, scientists can understand the age of the solar system, the processes of planet formation, and the history of asteroid collisions.
4. How do scientists determine if a rock is a genuine meteorite?
Scientists look for several key characteristics to identify a meteorite and distinguish it from terrestrial rocks. These features include:
- Fusion Crust: A thin, dark, glassy outer layer formed when the meteorite's surface melted during its fiery descent through the atmosphere.
- High Density: Due to their high iron content, most meteorites are significantly heavier than Earth rocks of a similar size.
- Magnetism: The presence of iron-nickel metal makes most meteorites magnetic.
- Regmaglypts: Thumbprint-like indentations on the surface caused by the ablation of material during atmospheric flight.
5. Why do meteoroids get so hot and glow when entering Earth's atmosphere?
A meteoroid's intense heat and glow are not primarily caused by friction, but by the extreme compression of air in front of it. As the meteoroid travels at hypersonic speeds (many kilometres per second), it rapidly compresses the atmospheric gases in its path. This compression heats the air to thousands of degrees Celsius, which in turn melts and vaporises the meteoroid's surface, creating the bright streak of light we call a meteor.
6. How can a piece of rock from space tell us the age of our solar system?
Meteorites serve as pristine time capsules from the birth of the solar system. Most are fragments of asteroids that formed at the same time as the planets but never got incorporated into them. Their chemical composition has remained largely unchanged for billions of years. Scientists use a technique called radiometric dating on specific isotopes within the meteorites to measure how long they have existed. This analysis consistently dates the oldest meteorites to approximately 4.6 billion years old, which is considered the most accurate age of our solar system.
7. Can a large meteorite impact really affect life across the entire planet?
Yes, a large meteorite impact can have catastrophic, planet-wide effects. While small meteorites pose no threat, an impact from an object several kilometres wide would be devastating. The most famous example is the Chicxulub impact 66 million years ago, believed to have caused the mass extinction of the dinosaurs. The impact would have thrown enormous amounts of dust and sulphur into the atmosphere, blocking sunlight, causing global cooling (an "impact winter"), and triggering widespread wildfires and tsunamis, leading to the collapse of ecosystems worldwide.
