Meteorite Recovery
Meteorites fall on every part of Earth equally, but they are found in very particular places. Antarctic ice fields and the world's hot deserts dominate the global recovery record because their surface conditions preserve specimens for long periods and make them stand out against light-colored, sparse terrain.
Written by Brian McDonald, IMCA #3323, Treasure Coast Meteorite Co.
Why Some Places Yield More Meteorites Than Others
Roughly 16 small meteoroids enter Earth's atmosphere every day, distributed evenly across the planet. Yet two thirds of all classified meteorites come from just two environments: Antarctica and a handful of hot deserts. The reason has nothing to do with where meteorites fall and everything to do with where they survive and where they can be seen.
To be recovered, a meteorite needs three things: a surface that does not bury it, a climate that does not destroy it, and a backdrop that makes it visible. Forests, jungles, oceans, and most temperate regions fail at least one of those tests. Polar ice and arid deserts succeed at all three, which is why the global meteorite catalog is dominated by them.
The Meteoritical Bulletin Database maintained by the Meteoritical Society now lists more than 75,000 classified meteorites. Tracing those entries back to their recovery locations reveals the consistent geography of meteorite finds.
Antarctica: The World's Largest Meteorite Source
Antarctica accounts for the majority of meteorites in scientific collections today. Since systematic recovery programs began in the 1970s, U.S., Japanese, European, and Chinese expeditions have collected more than 45,000 specimens from the East Antarctic ice sheet.
The reason Antarctica is so productive is a phenomenon known as ice flow concentration. Meteorites that fall on the high plateau become embedded in the ice and slowly travel downhill toward the coast over tens of thousands of years. When the flow encounters the Transantarctic Mountains, the ice is forced upward and gradually ablated away by Antarctic winds, exposing the meteorites that have been trapped within it. Some "blue ice" stranding fields in places like the Allan Hills and the Yamato Mountains have produced thousands of meteorites concentrated into areas of only a few square kilometers.
The U.S. effort is coordinated through the Antarctic Search for Meteorites (ANSMET) program, which has been recovering specimens nearly every austral summer since 1976. Antarctic meteorites are typically very well preserved because of the cold, dry conditions, which is why many of the most scientifically significant samples in modern collections come from there.
Hot Deserts: The Other Great Meteorite Region
After Antarctica, the world's hot deserts are the most productive meteorite-recovery environments. Several stand out.
Why Deserts Preserve Meteorites
The same conditions that make a desert a desert make it an excellent meteorite preserve. Low rainfall slows chemical weathering. Sparse vegetation means specimens lie exposed for centuries without being buried. Light-colored sand, gravel, or salt-pan surfaces provide a high-contrast background against which the dark color of a meteorite is easy to spot.
Many desert meteorites have terrestrial ages (the time since they fell to Earth) of tens of thousands of years. The Atacama Desert has yielded meteorites with terrestrial ages exceeding 2 million years, far older than any meteorites recovered from temperate climates. By comparison, a meteorite that falls in a temperate forest or grassland is usually unrecognizable within a few thousand years because of soil chemistry, plant cover, and weathering.
Meteorites do not fall more often in deserts. They simply survive long enough, and look different enough from the surrounding rocks, to be noticed.
Why Meteorites Are Rare in Temperate and Tropical Regions
Most of the world's land area is temperate or tropical, but these regions contribute only a small fraction of recovered meteorites. Several factors work against recovery in such environments.
Heavy rainfall accelerates weathering, particularly for iron-bearing meteorites that rust quickly under humid conditions. Dense vegetation hides specimens almost as soon as they fall. Soils rich in organic acids dissolve fusion crust and surface features that would otherwise make a meteorite identifiable. And ordinary terrestrial rocks are abundant in most temperate landscapes, so a dark stone in a field rarely stands out enough for a casual observer to notice it.
This is why the meteorites recovered from temperate regions overwhelmingly come from witnessed falls (someone sees the fireball and goes looking) rather than blind finds. The Park Forest fall in Illinois (2003), the Peekskill fall in New York (1992), and the Sutter's Mill fall in California (2012) are all examples of meteorites that would almost certainly never have been found if they had not been seen falling.
Where Meteorites Are Found in the United States
Within the U.S., meteorite finds are concentrated in the dry Southwest and the high plains. The dry lake beds of California and Nevada, the deserts of Arizona, and the Llano Estacado of Texas and New Mexico have all produced multiple classified specimens. Kansas, with its long history of agricultural plowing and its low surface erosion, has been particularly productive for a Midwestern state and is home to the famous Brenham pallasite strewnfield.
Eastern and northeastern states yield few meteorites compared to the dry West, and most of the ones that are recovered there come from witnessed falls. Florida, despite being heavily populated, has produced fewer than ten classified meteorites in recorded history, which reflects both its dense vegetation and its moist climate.
Strewn Fields: Where Multiple Meteorites Cluster
When a meteoroid breaks apart in the atmosphere, the resulting fragments scatter across the ground in an elongated zone called a strewn field. Some strewn fields have produced hundreds or thousands of individual meteorites, and many of the world's most famous meteorite localities are strewn fields.
The Sikhote-Alin iron strewn field in eastern Russia (1947), the Campo del Cielo iron strewn field in Argentina (which dates back thousands of years), the Almahata Sitta strewn field in Sudan (2008), and the Chelyabinsk strewn field in Russia (2013) are all examples of single events that produced large numbers of recoverable meteorites concentrated within a defined area. Strewn fields are heavily targeted by professional hunters because finding one fragment statistically increases the chance of finding more nearby.
Related Questions
Browse Authentic Meteorites
Frequently Asked Questions
Where are most meteorites found?
Antarctica has produced the largest single share of meteorites in scientific collections, primarily through dedicated recovery programs since the 1970s. Hot deserts in Northwest Africa, Oman, the Atacama, and the Australian Nullarbor are the next most productive regions.
Why do so many meteorites come from Antarctica?
Antarctic ice flow concentrates meteorites near certain mountain ranges, where wind ablation exposes them on stranding fields. The cold, dry climate preserves specimens nearly indefinitely, and the white ice surface makes dark meteorites easy to spot.
Can meteorites fall in the United States?
Yes, meteorites fall in every U.S. state, but they are easiest to find in the dry Southwest, particularly on California and Nevada dry lake beds, the Arizona deserts, and the high plains of Texas and New Mexico.
What is a strewn field?
A strewn field is the area on the ground where multiple fragments from a single meteorite are scattered after the original body broke apart in the atmosphere. Famous strewn fields include Sikhote-Alin (Russia, 1947) and Campo del Cielo (Argentina).
Are meteorites ever found in forests or jungles?
Occasionally, but they are very difficult to find. Dense vegetation hides specimens, organic-rich soils weather them rapidly, and rainfall causes iron-bearing meteorites to rust away within a few thousand years. Almost all forest finds come from witnessed falls.
