Ordinary chondrite
Ordinary chondrites are the most common meteorites, divided into H, L and LL groups by how much iron they contain.
They are called ordinary chondrites simply because they are so common: roughly four out of five meteorites seen to fall belong to this class. They are stony meteorites packed with chondrules, small grains of metal and the minerals olivine and pyroxene.
Scientists divide them into three groups by iron content. H stands for high iron, L for low iron and LL for low iron, low metal. The groups probably come from at least three different parent asteroids. A number after the letters, from 3 to 6, gives the petrologic type, which shows how much the rock was heated on its parent body: type 3 is the least changed, while type 6 has been heated so much that chondrules are hard to see. The Chelyabinsk meteorite, which exploded over Russia in 2013, is an LL5 ordinary chondrite. Japan's Hayabusa mission brought dust back from the asteroid Itokawa in 2010, and it matched LL chondrites closely.
On a cut surface ordinary chondrites show grey rock speckled with bright metal flecks and, in many, visible round chondrules. Most will attract a magnet.
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Level: Explorer Ages 10 and up