
A meteorite is a solid object from space that survives its passage through the atmosphere and lands on a planetary surface.Meteorites are solid extraterrestrial bodies that have fallen onto a planet's surface. Sizes range from millimeter-sized dust to blocks several meters across. The main source is asteroids, but fragments from the Moon and Mars are also found. By composition, they are classified as stony meteorites (including chondrites and achondrites), iron meteorites, and stony-iron meteorites. Chondrites contain chondrules—millimeter-sized spheres formed by rapid cooling of matter in the protoplanetary disk.
The decisive moment in the recognition of meteorites was the event of 1803: after the meteorite shower in L'Aigle (France), Jean-Baptiste Biot collected eyewitness accounts and samples, convincing the Academy of Sciences. Meteoritics has developed at the intersection of astronomy, geology, and physics. X-ray diffraction and mass spectrometry have enabled detailed study of minerals and isotopic composition. The discovery of presolar grains—microscopic dust particles that survived supernova explosions before the birth of the Sun—opened a new chapter in the study of the history of matter.
Entering the atmosphere at speeds from 11 to 72 km/s, a meteoroid undergoes strong aerodynamic heating, melting, and mass loss (ablation). The glow is caused by the shock wave and ionization of air. Equations of motion considering drag and ablation allow calculation of trajectory and final mass. The annual influx of meteoritic material is about 40,000 tons, predominantly in the form of micrometeorites. Networks of observatory cameras (e.g., the Fireball Network) record bright fireballs, enabling reconstruction of the meteoroid's orbit. Mineralogical analysis relies on X-ray diffraction and Bragg's law: nλ = 2d sinθ.
Meteorites are free samples of ancient material, allowing us to study the composition of the protoplanetary cloud without space missions and find organic molecules—the building blocks of life.
The Allende meteorite, which fell in Mexico in 1969, is 4.567 billion years old—older than Earth.
















