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By Liz Miller
Observer Staff Writer 

68,000 lb Meteorite Unearthed in Argentina

One of the Largest Ever Found on Earth

 

September 27, 2016

Astronomy Association of Chaco

Gancedo is likely the second or third largest meteorite ever found on planet Earth.

Over the weekend, a work crew used a crane to hoist a 30-ton meteorite out of the Campo del Cielo (Field of Heaven) about 670 miles northwest of Buenos Aires, Argentina, on the border between the provinces of Chaco and Santiago del Estero.

The meteorite, named Gancedo, has been tentatively declared the second largest yet discovered on Earth. Careful weighing will have to be done before that title can be formally declared, as well as tests to confirm that it is an actual meteorite.

This confirmation seems likely.

The accurately named Campo del Cielo is blistered with craters caused by a powerful meteor shower 4000 to 4700 years ago. At least 26 craters spread across an area of less than 2 x 12 miles.

Excavation at the site has already revealed an estimated 100 tons of space debris.

The undisputed champion of meteorites is called Hoba and was found in Namibia almost a century ago. Hoba weighs a whopping 66 tons. Though it has been fully uncovered, it has never been moved from its discovery location due to its enormous size. Hoba is thought to have slammed into our planet about 80,000 years ago, and is estimated to be between 190 million and 410 million years.

Gancedo's competition for the second largest is El Chaco. Weighing in at 37 tons, Chaco is also from the Campo del Cielo, and is therefore a brother of Gancedo, so to speak, likely arrived in the same space shower.

"While we hoped for weights above what had been registered, we did not expect it to exceed 30 tons," the president of the Astronomy Association of Chaco, Mario Vesconi, told the Xinhua news agency. "The size and weight surprised us."

"We could compare the weight with the other large meteorite found in the province. Although we expected it to be heavier, we did not expect it to exceed 30 tons," Vesconi reported to the Argentinian government news service, Télam.

"We will weigh it again. Apart from wanting the added confidence of a double-check of the initial readings we took, the fact that its weight is such a surprise to us makes us want to recalibrate."

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About Meteorites

Eugen Zibiso

Hoba, the largest known meteorite on Earth, was declared a national monument in Namibia in 1955. It has never been moved, but is a popular tourist destination, visited by thousands each year.

A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the Earth's atmosphere and impact with the Earth's surface. When the object enters the atmosphere, various factors like friction, pressure, and chemical interactions with the atmospheric gases cause it to heat up and radiate that energy. It then becomes a meteor and forms a fireball, also known as a shooting/falling star; astronomers call the brightest examples "bolides." Meteorites that survive atmospheric entry and impact vary greatly in size. For geologists, a bolide is a meteorite large enough to create a crater.

Meteorites that are recovered after being observed as they transit the atmosphere or impact the Earth are called meteorite falls. All others are known as meteorite finds.

Meteorites have traditionally been divided into three broad categories: stony meteorites are rocks, mainly composed of silicate minerals; iron meteorites that are largely composed of metallic iron-nickel; and, stony-iron meteorites that contain large amounts of both metallic and rocky material. Modern classification schemes divide meteorites into groups according to their structure, chemical and isotopic composition and mineralogy. Meteorites smaller than 2 mm are classified as micrometeorites. Extraterrestrial meteorites are such objects that have impacted other celestial bodies, whether or not they have passed through an atmosphere. They have been found on the moon and Mars.

 

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