- May 27, 2020 - Planétarium Rio Tinto Alcan : Astronomical News
A century ago, a farmer discovered an enormous rock in the African soil: the Hoba meteorite. Weighing more than 60 tons, it’s the biggest meteorite ever found on Earth.
The story of that discovery began in 1920 on Hoba West farm in South West Africa, now know as Namibia. The farm at the time was occupied by Michael J. Henson, but was owned by the family of Jacobus Hermanus Brits. Hoba West farm is located 20 kilometers west of Grootfontein and 65 kilometers southeast of the mining town of Tsumeb.
One winter’s day in the year 1920, when he was out hunting, Mr. Brits discovered a strange black rock embedded in the white limestone. He cut off a piece and brought it to the manager of the regional mining company, who confirmed that it was a meteorite. Subsequent analyses demonstrated that the meteorite, now named Hoba, was a block of iron and nickel weighing no less than 60 tons. Which made it the biggest meteorite on Earth.
Mr. Henson then approached the Pretoria museum (the territory of South West Africa had belonged to the Union of South Africa since the end of the First World War) to find out the value of the meteorite, claiming to be the discoverer and the owner! On that point, the mining operation, the South West African Company, also claimed to be the meteorite’s owner, having invested money to analyze the object.
Moving a colossus
Members of the South African government were thinking of moving the meteorite to Pretoria. They weren’t the only ones thinking along those lines. Some people thought about taking it to England and even to the Museum of Natural History in New York. But everyone realized that moving such a mammoth object was impossible. Besides, government authorities were quick to point out that it was illegal to transport the meteorite out of the country.
Travel to the Grootfontein area was difficult at the time, a train trip taking several days. So only a handful of specialists made their way there to study the meteorite, often in a superficial way. And as a result, few people, even among scientists, knew of the existence of this stone descended from space.
Fame courtesy of the New York Times
The Hoba meteorite became known to the general public on February 23, 1929, when an Afrikaans newspaper published an article by astronomer Willem J. Luyten on meteors, including Hoba. In March the New York Times published two articles by Luyten on the Hoba meteorite (back then it went by the name of the Grootfontein meteorite), which brought it worldwide renown.
The eminent geologist L.J. Spencer of London’s British Museum visited the meteorite in 1929 and 1930. He published a substantial scientific article on the Hoba meteorite in 1932. That article is still considered essential for anyone interested in the subject. Since then, the meteorite has been the focus of numerous scientific studies.
The Hoba meteorite is square in shape, with sides measuring 2.95 by 2.84 meters and with an average thickness of 0.91 meters. It’s composed of 82 percent iron and 16 percent nickel. It’s an ataxite IVB meteorite; only 17 meteorites of that type are known in the world. Its mass is 60 tons. Some people reckon that at the time of its discovery the mass was 66 tons, but many fragments have been removed from it over time.
Protecting the meteorite for future generations
The Hoba meteorite was declared a national monument in 1955 by the South West African administration. In the 1980s the mining company Rössin Uranium Ltd., in concert with Namibia’s National Monuments Council, organized the site in such a way as to protect the meteorite from vandalism and to develop the educational aspect of this treasure of Namibia.
