Stones falling from the sky?
A shooting star, or meteor, is the flash of a small grain or rock (a meteoroid) burning in the atmosphere; a piece that survives to the ground is a meteorite. Old records tell of stones from the sky, but most 18th-century European scholars dismissed them as superstition. In 1794 Ernst Chladni argued that masses such as Siberia's "Pallas iron" came from space, and when thousands of stones rained on L'Aigle, France, in 1803, Jean-Baptiste Biot investigated and convinced scientists that meteorites really fall. In 1906 Daniel Barringer argued that a large crater in Arizona was made by an impact, not a volcano, which was later confirmed.
What meteorites tell us
Most meteorites are fragments from the asteroid belt between Mars and Jupiter, and a few were blasted off the Moon and Mars. Chondrites, the commonest stony meteorites, contain tiny grains called chondrules and preserve material from the formation of the Solar System almost unchanged; iron meteorites are thought to be pieces of the cores of melted asteroids. In 1956 Clair Patterson used lead isotopes in meteorites to date the Earth and Solar System at about 4.55 billion years. The Murchison meteorite, which fell in Australia in 1969, contains amino acids that appear to have formed in space. In 1996 structures in Martian meteorite ALH84001 were reported as possible signs of life, but many scientists now think they can largely be explained without biology. In 2020 Japan's Hayabusa2 returned samples from asteroid Ryugu, whose composition closely matches certain meteorites.
Impact history
Large impacts have changed Earth's history. In 1980 the Alvarez team found unusually high levels of iridium — an element common in meteorites — in rocks about 66 million years old and proposed that a giant impact caused the mass extinction that ended the non-avian dinosaurs; the later discovery of the Chicxulub crater in Mexico has given the idea wide support. In 1908 an airburst at Tunguska, Siberia, flattened a vast forest, and in 2013 an object about 20 m across exploded over Chelyabinsk, Russia, its shock wave injuring more than 1,000 people. Most meteorites are harmless, but if you find one, handle it with clean gloves or a bag rather than bare hands, note the location and contact a museum or geological institution. Debris from comets produces annual meteor showers, though these particles are mostly too small to become meteorites.
FAQ
- Are meteorites hot when they land?
- The surface melts into a dark fusion crust on the way down, but the interior keeps the cold of space, so most are reported not to be hot just after landing.
- How can I tell if a rock is a meteorite?
- Many are heavy, attract a magnet and may show a dark fusion crust, but many Earth rocks look similar, so a final identification needs expert analysis.
Sources reviewed: 2026-10-26
References
- Chladni, E. F. F. (1794). Über den Ursprung der von Pallas gefundenen und anderer ihr ähnlicher Eisenmassen. Riga: J. F. Hartknoch.
- Biot, J.-B. (1803). Relation d'un voyage fait dans le département de l'Orne pour constater la réalité d'un météore observé à l'Aigle. Paris: Baudouin.
- Barringer, D. M. (1906). Coon Mountain and its crater. Proceedings of the Academy of Natural Sciences of Philadelphia, 57, 861–886.
- Patterson, C. (1956). Age of meteorites and the earth. Geochimica et Cosmochimica Acta, 10(4), 230–237.
- Kvenvolden, K., et al. (1970). Evidence for extraterrestrial amino-acids and hydrocarbons in the Murchison meteorite. Nature, 228, 923–926.
- Alvarez, L. W., Alvarez, W., Asaro, F., & Michel, H. V. (1980). Extraterrestrial cause for the Cretaceous–Tertiary extinction. Science, 208(4448), 1095–1108.
- McKay, D. S., et al. (1996). Search for past life on Mars: possible relic biogenic activity in Martian meteorite ALH84001. Science, 273(5277), 924–930.
- Popova, O. P., et al. (2013). Chelyabinsk airburst, damage assessment, meteorite recovery, and characterization. Science, 342(6162), 1069–1073.
- Yada, T., et al. (2022). Preliminary analysis of the Hayabusa2 samples returned from C-type asteroid Ryugu. Nature Astronomy, 6, 214–220.