Iron meteorite – Campo del Cielo, Argentina

Campo del Cielo is one of the most famous iron meteorites, which struck the Campo del Cielo region of Argentina about 4-5 thousand years ago, leaving behind approximately 26 craters. This meteorite belongs to the IAB-MG group and is composed mainly of iron and nickel, with admixtures of cobalt, phosphorus and germanium. Approximately 100 tonnes of material have been found so far. The largest specimens, weighing 30.8 and 28.8 tonnes, are among the largest and heaviest single-piece meteorite pieces discovered to have hit the Earth.

Origin

The Campo del Cielo meteorite probably comes from the asteroid belt, a region of the solar system between the orbits of Mars and Jupiter where many asteroids and planetesimals are found.

The asteroid belt was formed from material that could not coalesce into a full-fledged planet due to the gravitational influence of Jupiter. A collision between these objects may have caused some of the larger bodies to break up, fragments of which then broke loose and put some of them on a collision course with Earth. Campo del Cielo is considered one of these fragments, which, after a long journey from the asteroid belt, landed on Earth.

History and discovery

The Campo del Cielo meteorite impacted the Earth approximately 4 000 to 5 000 years ago. The impact caused a series of craters scattered over an area of approximately 3,000 km². Local natives discovered iron fragments long before the arrival of Europeans and used them to make tools and weapons.

In 1576, the Spanish conquistadors learned of these "iron mountains" and launched the first official search. However, real scientific research and cataloguing of meteorites did not begin until the 20th century. To date, more than 100 tons of material have been found, making Campo del Cielo one of the world's heaviest meteorite finds.

Composition and structure

Campo del Cielo is predominantly composed of iron (about 92%) and nickel (about 6.7%), with small admixtures of other metals such as cobalt and phosphorus. It also contains characteristic crystalline structures, known as Widmanstätten patterns, which are visible when the surface of the meteorite is etched with acid. These patterns are the result of the slow cooling of the iron-nickel alloy in space and are a typical feature of iron meteorites.