Meteorites are rocks from outer space come in three basic groups, although there are many subgroups: stony, iron, and stony-iron.
In general, stony meteorites resemble material from Earth’s crust.
Iron meteorites are almost pure iron and nickel-90 percent iron and 10 percent nickel, the same metals that are believed to make up Earth’s core.
Stony-iron meteorites contain both types of material.
Meteorites all date back about 4.6 billion years, so it is safe to assume that they contain original matter that made the solar system.
A subgroup of stony meteorites, known as carbonaceous chondrites, also contain carbon and amino acids, two building blocks of life.
Chondrites come from asteroids that have never melted, and are the most ancient rocks in the Solar System.
The Murchison meteorite, which fell in Australia in 1969, was a carbonaceous chondrite.
The second largest meteorite, the Ahnighito which weighed 37.5 tons, fell in Greenland and for centuries supplied local inhabitants with iron for tools and weapons.
The explorer Robert Peary bought the Ahnighito and, in 1897, sold it to the American Museum of Natural History in New York City.