The stuff from which many meteorites are made is 4560 million years old, and has remained virtually unaltered since its formation. Mainly representing debris left over after the planets were constructed, meteorites carry a unique record of the earliest events during the birth of the Solar System.
Meteorites can be fragments of rock, metal and mixtures of rock and metal mostly broken from asteroids in solar orbits between Mars and Jupiter. These broad groupings, however, belie the diversity of rocks that fall to Earth and are recovered.
Our best estimate is that the world’s meteorite collections contain samples from at least 135 different asteroids, each having had an independent history since the formation of the Sun and its system of orbiting planets. A small army of planetary scientists in universities and museums around the world are currently involved in deciphering the cryptic clues presented by meteorites to understand the chemical and physical processes that led to the construction of the Solar System.
Of the more than 50,000 meteorites in collections around the world, the vast majority are chance finds. Over the past 300 years or so, only about 1100 worldwide have actually been seen falling before being quickly recovered. Of these, the phenomena associated with the fall of only 12 have been photographed, enabling the orbits of the objects that...