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How do stony meteorites differ from iron and stony-iron meteorites?
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Small body
Asteroid Ida and its satellite, Dactyl, photographed by the Galileo spacecraft on August 28, 1993, from a distance of about 10,870 km (6,750 miles). Ida is about 56 km (35 miles) long and shows the irregular shape and impact craters characteristic of many asteroids. The Galileo image revealed that Ida is accompanied by a tiny companion about 1.5 km (1 mile) wide, the first proof that some asteroids have natural satellites.
Meteorites are categorized into three primary groupsāstony meteorites, iron meteorites, and stony-iron meteoritesābased on the proportions of rock-forming minerals and nickel-iron metal they contain.1
- Stony meteorites: These are the most abundant, accounting for approximately 94 percent of all known meteorites. They consist primarily of silicate minerals. They are divided into chondrites, which were never molten, and achondrites, which were once molten.123
- Iron meteorites: These are composed almost entirely of nickel-iron metal. They represent about 5 percent of known meteorites and are thought to originate from the metallic cores of differentiated asteroids.21
- Stony-iron meteorites: Comprising only about 1 percent of meteorites, these are an intermediate type containing substantial, roughly equal amounts of both silicate minerals and nickel-iron metal. They include pallasites, which feature silicate crystals embedded in a metal matrix, and mesosiderites, which are impact breccias containing both rocky fragments and dispersed metal.24