Few meteorites on Earth have captured the imagination of scientists, collectors, and space enthusiasts quite like the Campo del Cielo Meteorite. Scattered across the plains of northern Argentina lies one of the world's most famous meteorite fields — a place where enormous fragments of iron from space crashed into Earth thousands of years ago.

Holding a piece of Campo del Cielo is like holding a fragment of the early Solar System itself. Long before dinosaurs walked the Earth, before continents looked as they do today, this ancient mass of metal was travelling through space. Today, its fragments remain among the most sought-after meteorites in private collections around the world. 

Quick Facts

Meteorite Name: Campo del Cielo

Meteorite Type: Iron Meteorite

Classification: Coarse Octahedrite, IAB Main Group (IAB-MG)

Location: Chaco and Santiago del Estero Provinces, Argentina

Discovery by Europeans: 1576

Estimated Fall Date: Approximately 4,200–4,700 years ago

Age of Meteorite Material: Approximately 4.5 billion years

Main Composition:

• Iron: Approximately 92.6%

• Nickel: Approximately 6.7%

• Cobalt: Approximately 0.43%

• Phosphorus: Approximately 0.25%

Known Craters: At least 26

Total Recovered Weight: More than 100 tonnes

Above: The Campo del Cielo strewn field is located in northern Argentina.

The Field of the Sky

The name Campo del Cielo translates from Spanish as "Field of the Sky" — a fitting name for one of the largest meteorite strewn fields ever discovered.

The impact site lies roughly 1,000 kilometres northwest of Buenos Aires, near the border between the provinces of Chaco and Santiago del Estero. The crater field stretches approximately 18.5 kilometres long and contains at least 26 known craters formed when a massive iron meteoroid broke apart during its descent through Earth's atmosphere.

Unlike many meteorites that leave only a single impact crater, Campo del Cielo created a chain of craters and impact pits as numerous fragments struck the ground over a large area.

Above: The Campo del Cielo crater and strewn field extends across a large area of Argentina.

A Discovery Known Long Before Scientists

Long before European explorers arrived in South America, the indigenous peoples of the region already knew about the strange iron masses scattered across the landscape.

Historical records indicate that Spanish authorities first learned of the iron deposits in 1576 after hearing stories from local indigenous groups. The native inhabitants reportedly described a fiery object falling from the sky and pointed explorers toward the enormous metallic masses.

At the time, many believed the metal came from an unusual iron deposit within the Earth rather than from space. It would take centuries before scientists confirmed the extraterrestrial origin of the mysterious iron.

A Violent Arrival

Scientists estimate that the original meteoroid was more than four metres in diameter before entering Earth's atmosphere. As it plunged toward the planet, intense heat and pressure caused it to fragment.

The pieces struck the ground approximately 4,200 to 4,700 years ago, producing a chain of craters across the Gran Chaco region. Carbon dating of charred wood found beneath some meteorite fragments helped establish the approximate age of the impact event.

The largest crater measures roughly 115 metres by 91 metres, while smaller craters and impact pits are scattered throughout the field.

An Ancient Visitor From the Birth of the Solar System

Although Campo del Cielo landed on Earth only a few thousand years ago, the meteorite itself is far older.

Scientists estimate that the metal formed approximately 4.5 billion years ago during the birth of the Solar System. The iron and nickel that make up the meteorite likely originated within the core of a large asteroid.

At some point, catastrophic collisions shattered this parent body, sending fragments into space. One of those fragments eventually crossed Earth's orbit and became Campo del Cielo.

In a very real sense, Campo del Cielo is a surviving piece of an ancient world that no longer exists.

Classification and Composition

Campo del Cielo belongs to a rare category known as an iron meteorite.

Only around 5% of all meteorites recovered on Earth are iron meteorites, making them far less common than stony meteorites. Campo del Cielo is classified as a coarse octahedrite within the IAB Main Group (IAB-MG).

Its composition is dominated by iron and nickel:

• Iron: approximately 92.6%

• Nickel: approximately 6.7%

• Cobalt: approximately 0.43%

• Phosphorus: approximately 0.25%

• Trace amounts of gallium, germanium and iridium

Researchers have also identified sulfides, phosphides, carbides and silicate inclusions within some specimens, making Campo del Cielo scientifically significant for understanding asteroid formation processes.

Above: A polished Campo del Cielo slice reveals the meteorite’s metallic internal structure.

The Beautiful Widmanstätten Pattern

One of the most fascinating features of Campo del Cielo appears when a specimen is cut, polished and etched with acid.

The surface reveals an intricate crystalline structure known as a Widmanstätten pattern — a geometric network of interlocking metallic crystals formed by extremely slow cooling inside an asteroid core.

These patterns could not form on Earth because they require cooling rates measured in only a few degrees per million years. In other words, the crystal structure visible inside Campo del Cielo records a cooling process that took place over millions of years in deep space.

Above: The famous Widmanstätten pattern formed as the asteroid core cooled slowly in space over millions of years.

The Giant Masses of Campo del Cielo

The Campo del Cielo field has produced some of the largest meteorites ever recovered on Earth.

Among the most famous specimens are:

• El Chaco – approximately 28.8 tonnes

• Gancedo – approximately 30.8 tonnes

• La Sorpresa – approximately 15 tonnes

• Mesón de Fierro – estimated at more than 15 tonnes

Together, recovered material from the Campo del Cielo strewn field exceeds 100 tonnes, making it one of the largest accumulations of meteoritic iron ever discovered.

Above: Some Campo del Cielo masses weigh more than 30 tonnes.

Why Collectors Love Campo del Cielo

Campo del Cielo occupies a special place in the meteorite collecting world.

Unlike many rare meteorites that are prohibitively expensive, Campo fragments are relatively accessible while still offering an authentic connection to space. Collectors appreciate the meteorite's rugged sculpted surface, natural regmaglypts, impressive weight, and beautiful etched structures.

Every specimen tells a story that began billions of years ago in the core of an ancient asteroid.

Above: Campo del Cielo remains one of the most popular meteorites among collectors worldwide.

Fun Facts

• Campo del Cielo means "Field of the Sky."

• More than 26 craters have been identified within the impact field.

• The meteorite fell approximately 4,200–4,700 years ago.

• The metal formed around 4.5 billion years ago.

• Some recovered specimens weigh more than 30 tonnes.

• Campo del Cielo is one of the most widely collected iron meteorites in the world.

• Indigenous peoples knew about the meteorite field centuries before European explorers documented it.

Caring for Campo del Cielo Meteorites

Because Campo del Cielo is primarily composed of iron, it can develop rust if exposed to moisture.

To help preserve a specimen:

• Store it in a dry environment

• Avoid prolonged exposure to humidity

• Handle polished pieces with clean hands

• Consider silica gel packs for display cases

• Lightly oil untreated specimens if recommended by the seller

Proper care will help ensure your meteorite remains stable for generations.

A Fragment of Deep Time

Above: A polished Campo del Cielo meteorite slice displaying its extraterrestrial metallic beauty.

Few objects connect us to the history of the Solar System as directly as a meteorite.

Campo del Cielo is more than an unusual rock or a collector's item. It is a survivor from the earliest days of planetary formation — a fragment of an asteroid core that spent billions of years travelling through space before crashing into the plains of Argentina.

When you hold a piece of Campo del Cielo, you are holding material that predates Earth itself. It is a tangible reminder that our planet exists within a much larger cosmic story — one written across billions of years and countless kilometres of space.