Meteorite Science
The largest meteorite ever found on Earth is Hoba, an iron meteorite lying where it was found in about 1920 near Grootfontein, Namibia. The Meteoritical Bulletin records its mass as 60 metric tons, and Buchwald's Handbook of Iron Meteorites describes it as the largest single meteorite fragment known on Earth. It has never been moved and has been a national monument since 1955.
Written by Brian McDonald, IMCA #3323, Treasure Coast Meteorite Co.
The Hoba Meteorite
The Hoba meteorite, Grootfontein, Namibia. Its nearly square upper surface measures about 2.95 by 2.84 meters (Buchwald 1975). It has never been moved from where it was found. Photo: Giraud Patrick / Wikimedia Commons / CC BY 2.5
Hoba was found in about 1920 on the farm Hoba West, roughly 20 kilometers west of Grootfontein. Accounts of the discovery differ in their details. Buchwald's Handbook records the exposed upper surface as nearly square, 295 by 284 centimeters, with a thickness of 111 to 122 centimeters at one end and 55 to 75 centimeters at the other. Published analyses give about 16.4 percent nickel and 0.76 percent cobalt, with the balance mostly iron. The Meteoritical Bulletin classifies Hoba as Iron, IVB. Buchwald describes its structure as a nickel-rich ataxite, explained in the research section below.
No crater and no crushed rock have been found at the site (Buchwald 1975). McCorkell and colleagues (1968) proposed that the mass was later covered by a layer of surface limestone during a wetter period, and estimated from cosmogenic isotopes that Hoba has been on Earth for less than 80,000 years. Why a mass this large left no crater has not, as far as we could find, been settled in the published literature. The explanation usually offered is that the atmosphere removed most of its speed before it reached the ground, but we have not located a peer-reviewed study that tests it.
Hoba was declared a national monument in 1955 and still rests where it was found (Buchwald 1975).
Before the mass was protected, specimens were cut from it with an oxy-acetylene torch and removed by drilling and chiseling. Buchwald estimated in 1975 that probably no more than about 20 kilograms had been removed in total. Small pieces of Hoba are held in museum collections in Philadelphia, Washington, London and New York, among others.
The Largest Meteorites on Record
Hoba is the largest single meteorite known. The table lists the recorded mass of each meteorite as given in the Meteoritical Bulletin Database. For meteorites recovered as many pieces, that figure is the total for the whole meteorite, not the size of its largest piece.
| Meteorite | Recorded mass | Country | Classification |
|---|---|---|---|
| Hoba | 60 t | Namibia | Iron, IVB (ataxite) |
| Cape York | 58.2 t, several masses | Greenland | Iron, IIIAB (medium octahedrite) |
| Campo del Cielo | 50 t, many masses | Argentina | Iron, IAB-MG (coarse octahedrite) |
| Bacubirito | 22 t | Mexico | Iron, ungrouped (finest octahedrite) |
| Mbosi | 16 t | Tanzania | Iron, ungrouped (medium octahedrite) |
| Willamette | 15.5 t | United States | Iron, IIIAB (medium octahedrite) |
Masses and classifications from the Meteoritical Bulletin Database, checked September 2026. The database cautions that its masses are not authoritative and may be rounded. Structural terms in parentheses are from Buchwald (1975), because the Bulletin records iron meteorites by chemical group only. Cape York and Campo del Cielo are totals for many separate masses. The largest single Cape York mass, Ahnighito, weighs 30,875 kg (Ebel 2006), and the largest Campo del Cielo masses are discussed below.
Notable Meteorites in Detail
Cape York and Ahnighito
The Cape York meteorite is a group of large iron masses from Melville Bay in northwest Greenland. When the explorer John Ross visited the area in 1818, local Inuit people were using knives and tools made from its metal. Robert Peary was guided to three masses known as the Woman, the Dog and the Tent, and removed the largest, the Tent, in 1897 after two seasons of effort. Renamed Ahnighito, it was weighed in 1958 at 30,875 kg (68,080 lb). At the American Museum of Natural History it was mounted on six pillars that run through the basement to bedrock (Ebel 2006).
Other masses have been found since, the largest being Agpalilik at 20,140 kg, recovered in 1963 and now in Copenhagen (Ebel 2006, citing Buchwald 1975). The Meteoritical Bulletin records 58.2 metric tons for the meteorite as a whole. The date of the fall is not known. Buchwald notes that the distribution of the masses does not fit a fall during the less than 1,000 years that people have lived in the area.
Willamette Meteorite
Willamette is the largest meteorite found in the United States (Ebel 2006). Ellis Hughes found it in 1902 near the village of Willamette, now part of West Linn, on land belonging to the Oregon Iron and Steel Company. According to Ward's 1904 account, quoted in Buchwald, Hughes and his 15-year-old son moved it nearly three quarters of a mile to his own property in 1903 with a small horse and improvised equipment. The company sued and won ownership, and the meteorite was bought for the American Museum of Natural History in 1906 (Ebel 2006).
Its deeply pitted upper surface formed on Earth, not in flight. Rainwater dissolved sulfur from troilite (iron sulfide) inclusions, producing sulfuric acid that etched out cavities up to about 50 cm deep and removed an estimated six tons of metal (Ebel 2006, citing Buchwald 1975). The Bulletin records 15.5 metric tons. A railroad scale weighing reported in 1906 gave 14.1 metric tons (Buchwald 1975).
The Willamette meteorite on display at the American Museum of Natural History, New York. At 15.5 tons it is the largest meteorite found in the United States. The deep pits were formed by post-landing weathering, not atmospheric entry. Photo: Mike Cassano / Wikimedia Commons / CC BY 2.0
Campo del Cielo
Campo del Cielo is a shower of iron masses spread across the Gran Chaco of northern Argentina. Spanish explorers brought back fragments of a large mass called Mesón de Fierro in about 1576 (Buchwald 1975, citing Alvarez 1926). Cassidy and Renard (1996) describe a field of at least 20 small craters, elongated over about 3 by 18.5 km because the meteoroid arrived at a low angle, roughly 9 degrees from horizontal. They date the fall to about 4,000 years ago. An earlier radiocarbon date on charred wood from one crater gave 5,800 ± 200 years (Cassidy and colleagues 1965), and the European Space Agency gives the age as 4,000 to 5,000 years.
The Meteoritical Bulletin records a total of 50 metric tons, while the European Space Agency states that more than 100 tonnes have been recovered. We have not found a published reconciliation of the two figures, and neither is the mass of a single piece. The largest documented mass, known as El Chaco, was weighed on a truck scale at 33,400 kg after excavation and later registered 36,000 kg on a crane scale (Ebel 2006, citing Cassidy and Renard 1996). Campo del Cielo material is among the most widely available iron meteorites on the collector market.
Why Large Meteorites Are So Rare
The Earth's atmosphere is a remarkably effective shield. Most meteoroids that enter it are destroyed entirely before reaching the ground, and even those that survive lose a significant fraction of their mass to ablation during the descent. The larger an object, the more mass it retains relative to the surface area experiencing heating, which is why larger meteoroids are more likely to produce recoverable meteorites. But the forces involved in atmospheric entry are also proportionally destructive.
A meteoroid large enough to survive intact to the surface carries enormous kinetic energy. The transition from space rock to crater involves energy releases that can far exceed nuclear weapons. Objects like Hoba are rare precisely because the conditions that allow intact survival are very narrow.
For a large iron meteoroid to reach the ground as a single mass, it has to be coherent, high-density metal rather than more fragile stony material, and it has to avoid breaking apart during descent. Campo del Cielo shows the other outcome: a low-angle entry, about 9 degrees according to Cassidy and Renard (1996), in which the meteoroid broke up and spread its masses along a narrow field many kilometers long.
Where Large Iron Meteorites Come From
Every large iron meteorite represents a piece of an asteroid's metallic core. In the early solar system, some asteroids grew large enough and hot enough for their interiors to melt and differentiate. Heavy iron and nickel sank to form a metallic core, just as happened inside Earth. When these differentiated asteroids were later disrupted by collisions, their cores were exposed and fragmented. The resulting iron masses drifted through the solar system until some of them encountered Earth.
The composition of iron meteorites reflects this origin. High nickel content, chemical group classifications tied to distinct parent bodies, and the Widmanstätten crystal structure that forms only during millions of years of slow cooling deep inside an asteroid all point to the same history: these are fragments of worlds that no longer exist.
Related Questions
What the research reports
The Meteoritical Bulletin Database is the official record for every meteorite on this page, and the masses and classifications in the table come from it. For iron meteorites the Bulletin records the chemical group only, such as IVB or IIIAB. The structural terms used here, ataxite and octahedrite, come from Vagn Buchwald's Handbook of Iron Meteorites, the standard reference on iron meteorite structure, which the Bulletin links from each entry. Findings come from the authors' own samples and methods and are given as the studies state them.
Buchwald, V. F. (1975). Handbook of Iron Meteorites. University of California Press, 3 volumes.
Buchwald classifies iron meteorites by the structure revealed when a cut face is etched. Octahedrites show Widmanstätten bands of the nickel-poor alloy kamacite, and he grades them by band width. Cape York (1.20 mm), Willamette (1.05 mm) and Mbosi (0.80 mm) are medium octahedrites, Campo del Cielo (about 3 mm) is a coarse octahedrite, and Bacubirito (0.08 mm) is a finest octahedrite. He flags Bacubirito and Mbosi as chemically anomalous, consistent with their later classification as ungrouped irons. Hoba shows no visible kamacite bands in etched sections, only an oriented sheen, which is why he describes it as a nickel-rich ataxite. His entry for Hoba also gives its dimensions and composition, summarizes the finding of McCorkell and colleagues (1968) that Hoba has been on Earth for less than 80,000 years, and records that no crater has been found.
Ebel, D. S. (2006). History of the American Museum of Natural History meteorite collection. Geological Society, London, Special Publications 256, 267 to 289.
A peer-reviewed history by the museum's meteorite curator. It is the source here for the recovery and weighing of Ahnighito, the Agpalilik mass, the Willamette ownership case, and the explanation of Willamette's pits as weathering driven by sulfuric acid from troilite, which Ebel attributes to Buchwald. It also reports the El Chaco weighings at Campo del Cielo.
Cassidy, W. A. and Renard, M. L. (1996). Discovering research value in the Campo del Cielo, Argentina, meteorite craters. Meteoritics & Planetary Science 31, 433 to 448.
Reviews the field data for the Campo del Cielo crater field: at least 20 small craters formed by multi-ton fragments, a fall about 4,000 years ago, an entry angle of roughly 9 degrees, and an elongated field of about 3 by 18.5 km. The European Space Agency's summary of the site gives an age of 4,000 to 5,000 years and more than 100 tonnes recovered, figures that differ from both this study and the Bulletin total.
Masses and classifications last checked against the Meteoritical Bulletin Database in September 2026: Hoba, Cape York, Campo del Cielo, Bacubirito, Mbosi, Willamette.
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Frequently Asked Questions
Where is the Hoba meteorite located?
Hoba lies where it was found in about 1920, on the farm Hoba West near Grootfontein in Namibia. It has never been moved and has been a national monument since 1955.
Why did the Hoba meteorite not create a crater?
No crater or crushed rock has been found at the site (Buchwald 1975). The explanation usually offered is that the atmosphere slowed the mass enough that it arrived at low speed, but we have not found a peer-reviewed study that tests this. McCorkell and colleagues (1968) proposed that the mass was later partly buried by surface limestone.
What is the largest meteorite in the United States?
Willamette, found in Oregon in 1902, is the largest meteorite found in the United States. The Meteoritical Bulletin records 15.5 metric tons. It is on display at the American Museum of Natural History in New York.
Are there larger meteorites in space?
Yes, by a considerable margin. Many asteroids in the solar system are vastly larger than any meteorite found on Earth. The asteroid Ceres, the largest object in the asteroid belt, is about 940 kilometers across. Even much smaller near-Earth asteroids dwarf the Hoba meteorite. What reaches Earth's surface as a meteorite is only the material that survives atmospheric entry intact.
What type of meteorite is Hoba?
The Meteoritical Bulletin classifies Hoba as Iron, IVB, which is a chemical group. Buchwald's Handbook of Iron Meteorites (1975) describes its structure as a nickel-rich ataxite: etched sections show no visible kamacite bands, only an oriented sheen, unlike the Widmanstätten pattern seen in octahedrites. Published analyses give about 16.4 percent nickel.
Can pieces of famous meteorites like Campo del Cielo be purchased?
Yes. Campo del Cielo meteorite material is among the most widely available iron meteorites on the collector market. Fragments ranging from small slices to larger individuals are regularly sold by specialist dealers. Hoba is a protected national monument and is not available to collectors.
