Meteorite

When you visit Willis Observatory you can hold a 5.1 pound Campo del Cielo meteorite which is older than life on earth. The age of the meteorite is estimated to be 4.5 billion years old, formed as part of the development of our solar system.

Campo del Cielo (“Field of Heaven”) refers to a group of iron meterorites or to the area where they were found in Argentina. The crater field covers an area of 1.9 by 11.5 miles and contains at least 26 craters, the largest being 377 by 299 feet.

The craters' age is estimated as 4,000–5,000 years. The craters, containing iron masses, were reported in 1576, but were already well known to the aboriginal inhabitants of the area. The craters and the area around contain numerous fragments of an iron meteorite. The total weight of the pieces so far recovered is about 100 tonnes, making the meteorite possibly the heaviest one ever recovered on Earth.

In 1576, the governor of a province in Northern Argentina commissioned the military to search for a huge mass of iron, which he had heard that Natives used for their weapons. The Natives claimed that the mass had fallen from the sky in a place they called Piguem Nonralta which the Spanish translated as Campo del Cielo ("Field of Heaven"). The expedition found a large mass of metal protruding out of the soil. They assumed it was an iron mine and brought back a few samples, which were described as being of unusual purity. The governor documented the expedition and deposited the report in the Archivo General de Indias in Seville, but it was quickly forgotten and later reports on that area merely repeated the Native legends.

Following the legends, in 1774 Don Bartolomé Francisco de Maguna rediscovered the iron mass which he called el Meson de Fierro ("the Table of Iron"). Maguna thought the mass was the tip of an iron vein. The next expedition, led by Rubin de Celis in 1783, used explosives to clear the ground around the mass and found that it was probably a single stone. Celis estimated its mass as 15 tonnes and abandoned it as worthless. He himself did not believe that the stone had fallen from the sky and assumed that it had formed by a volcanic eruption. However, he sent the samples to the Royal Society of London and published his report in the Philosophical Transactions of the Royal Society.  Those samples were later analyzed and found to contain 90% iron and 10% nickel and assigned to a meteoritic origin.

Later, many iron pieces were found in the area weighing from a few milligrams to 34 tonnes. A mass of about 1 tonne known as Otumpa was located in 1803. A 634 kilograms (1,398 lb) portion of this mass was taken to Buenos Aires in 1813 and later donated to the British Museum.

Samples of charred wood were taken from beneath the meteorite fragments and analyzed for carbon 14 composition. The results indicate the date of the fall to be around 4,200–4,700 years ago, or 2,200–2,700 years BC.

The average composition of the Campo del Cielo meteorites is 6.67% Ni, 0.43% Co, 0.25% P, 87 ppm Ga, 407 ppm Ge, and 3.6 ppm Ir, with the remaining 92.6% being iron.

Moon Rock

Our slice of a moon rock has an official name.  It is a slice from meteorite NWA 11273.  The moon rock was analyzed by Dr. Antony Irving of the University of Washington. Dr. Irving determined the moon rock is a lunar feldspathic breccia, a lunar meteorite. Our moon meteorite was accepted and published in the Meteoritical Bulletin.

https://www.lpi.usra.edu/meteor/metbull.php?code=66064

From this meteorite, we got the slice, NWA11273-4-618.

We know our moon had a very violent past from looking at all of its impact craters.  Earth’s gravity caught some of the debris from the violent collisions/impacts.