Meteorites
Meteorites are natural objects made of iron & stone which fall from space through the Earth’s atmosphere. Their size ranges from dust-sized particles to huge lumps weighing many tonnes.
Meteorites have been falling throughout the Earth’s history. They are very important, as they record the Solar System’s birth (4,560 million years ago), and its subsequent history.
The first written records of meteorites are in cuneiform, about 1900 BC. A decade or two ago, fossilized meteorites that fell to Earth over 450 million years ago were recently found in Sweden.
Meteorites are made up of the same elements as the Earth & Sun. These elements combine to form over 300 different minerals - some of these minerals are not found on Earth.
The abundance & types of minerals in the meteorites are used to classify them into three categories: stones (chondrites & achondrites), stony-irons (e.g. pallasites), and irons.
In recent decades, a lot of very well-preserved meteorites have been found on the surface of the Antarctic ice-sheet. They had accumulated there over hundreds of years.
