0 WHAT IS THE LARGEST METEORITE FOUND ON EARTH?

In 1920, a farmer was plowing a field near Grootfontein, Namibia when his plow suddenly screeched to a halt. Curious about what he had run into he dug in the soil to find a large piece of metal. The large metal mass quickly attracted the attention of scientists and others, who identified it as a meteorite and removed the soil around it.

Although excavated, the meteorite has not been moved from its location of discovery because of its great weight. However, many pieces have been removed for scientific study and through vandalism.


Hoba

The Hoba Meteorite in 2006

The farmer had discovered a 66-ton iron meteorite - the largest single meteorite ever found and the largest piece of iron ever found near Earth's surface. It is tabular in shape and about nine feet long, nine feet wide (3 metres x 3 metres) and about three feet thick (0.91 metres). It was given the name "Hoba" because it was discovered on a farm named "Hoba West".

The Hoba meteorite is thought to have landed less than 80,000 years ago.  It is surprising that this meteorite is not surrounded by a crater. Objects of this size should punch through the atmosphere at a very high rate of speed and hit Earth with enough force to blast a significant crater. No crater is present around the site of the meteorite. This suggests that it fell to earth at a lower rate of speed than expected. 

It is inferred that the Earth's atmosphere slowed the object down to the point that it fell to the surface at terminal velocity, thereby remaining intact and causing little excavation. The meteorite is unusual in that it is flat on both major surfaces, possibly causing it to have skipped across the top of the atmosphere in the way a flat stone skips on water.

It is composed of about 84% iron, 16% nickel, and trace amounts of cobalt and other metals. An abundance of iron oxides in the soil around the meteorite suggests that it was much larger than 66 tons when it landed and has suffered significant losses from oxidation.

The Hoba Meteorite in 1967

In the attempt to control vandalism, the Government of Namibia (then South West Africa), declared the Hoba meteorite to be a National Monument on March 15, 1955 with permission of Mrs. O. Scheel who was the owner of the farm at that time.  In 1985, Rossing Uranium Ltd. made resources and funds available to the Namibian Government to provide additional protection against vandalism. In 1987 Mr. J. Engelbrecht, the owner of Hoba West farm, donated the meteorite and the site where it lies to the State for "educational" purposes. Later that year, the Government opened a tourist centre at the site. As a result of these developments, vandalism of the Hoba meteorite has ceased and it is now visited by thousands of tourists every year.







Resource(s):
geology.com
wikipedia