Meteorites

In celebration of Global Astronomy Month, let’s learn about extra-terrestrial rocks.

Rocks from outer space that ended up here on earth are called meteorites. These space rocks could either be fragments of an asteroid, a comet, the moon, or other planets that survive the journey through the earth’s atmosphere.  As these fragments rapidly enter the atmosphere, they begin to burn and flame up. Under the night sky, these flaming debris are commonly referred to as shooting stars. Some of these rocks are too small and turn to ash as they enter while those large enough to withstand the heat, land on the ground as meteorites.

There are various types of meteorites depending on their composition, but three main types have been identified so far. Iron meteorites are mostly composed of iron and nickel.  Stony meteorites are composed mainly of silicate minerals. Meteorites that have an equal amount of silicate minerals and iron-nickel metals are called stony-iron meteorites. There are still quite a few more sub-types identified under these three major classifications. 

At the former #NationalMuseumPH Planetarium, you may remember seeing actual meteorites in one of the displays. One of the meteorites is an iron-type meteorite called Sikhote-Alin Fall that fell in the Maritime Territory of Russia in 1947. It was part of the largest ever meteorite fall in modern history. The other meteorite is the NWA-869 found in Northwest Africa in 2000. This stony meteorite is part of Asteroid 433, also called Eros. 

In geology, meteorites play an important role in our understanding of the Earth’s history. Most meteorites are older than terrestrial rocks. As such, they contain within them information that will help understand planetary origins and processes.

#GAM2022

Text and image by the NMP Geology and Paleontology Division

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