What is the largest meteorite ever found?
The largest known meteorite is the Hoba iron in Namibia, estimated at about 60 tonnes; it was found in 1920 and still lies where it landed.
The heaviest single meteorite known is Hoba, an iron meteorite on a farm near Grootfontein in northern Namibia. In 1920, according to the usual account, the farmer was ploughing a field when his plough struck something hard. Digging revealed a flat, slab-like block of metal about 2.7 m long and wide and roughly 1 m thick. Its mass is estimated at around 60 tonnes, although the exact figure is uncertain because it has never been weighed, and pieces have been removed and lost to weathering over time.
Hoba is unusual in several ways. It is an ataxite, a type of iron meteorite rich in nickel, at about 16%, which gives it a fine-grained structure with no visible crystal pattern when etched. And it has never been moved: it is far too heavy, and it is now protected as a national monument. Visitors can walk up to it in a small amphitheatre built around it. Scientists think its flat shape may have helped it slow down in the atmosphere, so that it landed without blasting out a large crater; no crater has been found around it.
Other giants follow some way behind. Ahnighito, the largest piece of the Cape York meteorite from Greenland, weighs about 31 tonnes and is on display in a New York museum. In Argentina, the Campo del Cielo strewn field has yielded several masses of about 30 tonnes, such as El Chaco and Gancedo. The Willamette iron, about 15.5 tonnes, is the largest found in the United States.
Note that these are single pieces. Much bigger objects have struck Earth, but they were largely vaporised or shattered on impact. The asteroid that formed Meteor Crater in Arizona was perhaps 50 m across, yet only scattered fragments of it survive.