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Iron Meteorite found in Sibera Image Credit: Raab

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The Extraterrestrial Traveler by Joshua Rice

What do you think of when you hear the word meteorite? A giant space rock that is crashing into Earth? Well you are close! A meteorite is an extraterrestrial rock that enters Earth’s atmosphere, falling to the surface of our planet. It may be a giant rock when it starts crashing into Earth, but it begins to burn up when it hits Earth’s atmosphere. By the time it actually hits the ground, it is usually quite small. But what exactly are meteorites and where do they come from? Often people think of meteorites as just space rocks, but this is only partially true. There are several different types of meteorites, with one of the most common being iron meteorites. Iron meteorites are composed of about ninety percent iron, with nickel and some other trace elements. This type of meteorite may even have trace amounts of precious metals in it, such as iridium, gallium, or even gold.

By now perhaps you are wondering where these meteorites came from. Well from what scientists can tell, iron meteorites originate from the depths of our Solar System. Specifically, iron meteorites come from the cores of very small, young planets. When our Solar System was just beginning, there was an abundance of small planets forming with iron and nickel cores. Unfortunately, the early stages of our Solar System were very unorganized. This resulted in many collisions that occurred between the different young planets, tearing them apart. These pieces of small, young planets from catastrophic collisions are what make up the iron meteorites we see today. In fact, because these meteorites are from the early stages of planet formation, iron meteorites offer scientists a great snapshot of the early stages of planetary development in our Solar System. So the next time you encounter a meteorite, remember that not all meteorites are created equal!

 

Sources:

Notkin, Geoffrey. Iron Meteorites, The Heart of Long-Vanished Asteroids [Internet]. Geoffrey Notkin; [cited 2013 Mar 15] .

Yang, Jijin , Goldstein, Joseph I, Scott, Edward  RD. 2007. Iron Meteorite Evidence for Early Formation and Catastrophic Disruption of Protoplanets. Nature.  446:888-891.

Bottke, William F, Nesvorny, David , Grimm, Robert E ,Morbidelli, Alessandro , O’Brien, David P. 2006. Iron Meteorites as Remnants of Planetismals Formed in the Terrestrial Planet Region. Nature. 439: 821-824.

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