meteorite

A meteorite is a rock (or hunk of iron) that is the remnant of a meteor (a meteor being the visible manifestation of a meteoroid entering Earth atmosphere). Meteorites are found all over the world, but some glacier formations, e.g., in the Antarctic, gather them as time passes. A micrometeorite is a microscopic meteorite. Meteorites have been studied, and conclusions drawn regarding their source and origin mesh with and contribute to the history and formation of the solar system and its planets. Some are discerned to be fragments from impacts on the Moon, and others from Mars, and yet others from past, broken-up asteroids. Given these conclusions, they are valuable sources of information about these bodies. Many meteorites are thought to have been orbiting the Sun for nearly its entire lifetime, revealing the early history of the solar system. In particular, signs of melting indicate some past time and circumstance when conditions existed to produce it. Study has discerned numerous classes of meteorites, some of the overall classes of high interest being:

• iron meteorites.
• stony meteorites.
• stony-iron meteorites (with both).

Among stony meteorites:

• chondrites (with embedded pieces of distinct material termed chondrules).
• achondrites (without chondrules).
• carbonaceous chondrites (carbonaceous indicating they include carbon, typically up to about 3%).