Hunt continues for meteorite fragments scattered across northern Argentina
By Julieta Barrera
Buenos Aires, Apr 6 (efe-epa).- Fragments of meteorites that made impact with Earth’s surface around 4,000 years ago still remain to be discovered in “Campo del Cielo” (Field of Heaven), a vast area of northern Argentina.
“It’s one of the world’s largest meteorite dispersion areas and the only one from which such a quantity of mass was recovered,” Mario Vesconi, president of the Chaco Astronomy Association (ACHA), researcher, geophysics expert and co-discoverer of six of the site’s eight multi-ton meteorites, told Efe.
The 400 tons of siderites (meteorites that largely consist of an iron-nickel alloy known as meteoric iron) that struck the ground at a speed of 14,000 kilometers (8,700 miles) per hour – half of the original 800-ton asteroid’s total mass was lost by ablation – were dispersed over a 240,000-hectare (926-square-mile) area straddling the present-day provinces of Chaco and Santiago del Estero.
“We have two areas defined: the crater field where these 26, 28 craters are located, and the even larger dispersion area of small, or not so small, fragments,” Vesconi said.
More than 100 metric tons have already been recovered, with the “El Chaco” meteorite (33,400 kilograms) – which was discovered in 1969 and is the second-biggest worldwide after the 66,000-kg Hoba in Namibia – and the “Gancedo” meteorite (27,740 kg), found in 2016, making up more than half of the total.
Since 2015, all the meteorite finds are available for viewing at the “Campo del Cielo” Scientific and Educational Park, located at a likenamed natural and cultural reserve in Chaco.
“You arrive and you can visit six, seven craters with preserved roads, with signage, see where the work was carried out,” Vesconi said.
Legends and myths about metallic objects scattered around the region led as early as 1576 to the first expeditions in search of resources for the Spanish crown.
The reports from those missions indicated the discovery of a large metallic fragment known as “Meson de Fierro” (Table of Iron) weighing about 23,000 kg, although all trace of that find was later lost.
Other large fragments were later discovered by local residents and some craters were studied.
An important period of discovery then occurred between 1962 and 1972, when late American geologist William Cassidy found 16 impact craters and several meteorites, including “El Chaco.”
Years later, Vesconi and his team took charge of field work in the area and published their results.
“I remember one day I received an email from the University of Pittsburgh. It was Dr. William Cassidy no less. He was a hero to us,” the researcher said.
Cassidy, who had funding from NASA to conduct three years of impact structure studies at “Campo del Cielo,” had reviewed some of the work carried out by Vesconi and his team and invited them to join his research group.
In the 1960s, Cassidy enlisted the help of local residents to locate “dams” or “dry ponds” that might turn out to be craters, although now high-resolution satellite imagery and other technology make the task easier.
Vesconi estimates the remaining fragments can be recovered in five years and hopes 2021 will be fruitful after 2020 was lost due to the pandemic. EFE-EPA