Arizona’s Meteor Crater and other scars leftover from collisions with space rocks continue to serve up their secrets.
Meteor Crater formed some 50,000 years ago. It represents the best preserved meteor impact site in the world, measuring some 700 feet deep (213 meters), more than 4,000 feet across (1,219 meters), and 2.4 miles (3.9 kilometers) in circumference.
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Natural laboratory
A recurring visitor to the crash site is Dan Durda, a research scientist at the Southwest Research Institute (SwRI) in Boulder, Colorado.
“Meteor Crater is the best-preserved and exposed impact crater on Earth,” Durda tells Space.com. “That makes it the perfect natural laboratory for impact crater studies. The crater is still providing new insights every year, so continued studies there are really important.”
Similar in view is Christian Koeberl at the Department of Lithospheric Researchwithin the University of Vienna in Austria. He chairs the Barringer Crater Company (BCC) scientific advisory committee. The Barringer Crater Company has introduced grants to support students and early career researchers who study terrestrial impact craters, for better understanding of these craters and their formations, and also to encourage students to go into such important research directions.
“Barringer Crater — also known as Meteor Crater — was one of the first, if not the first, crater recognized on Earth as being of impact origin in the early 20th century,” Koeberl tells Space.com.
The recognition of impact craters on the Earth is difficult, said Koeberl, because active geological and atmospheric processes on our planet tend to obscure or erase the impact record in geologically short time periods.
“Despite limited information about the early impact record we know that impacts had severe effects on the geological and biological evolution on Earth,” said Koeberl. For example, a large impact event on Earth marks the transition from the Cretaceous to the Paleogene eras, about 66 million years ago, he added.
The most iconic species that has fallen victim to an impact, the dinosaurs, “literally had no chance,” Koeberl said.
Read more: 10 Earth impact craters you must see
High-energy geological event
Morphological and geophysical surveys are important for the recognition of anomalous subsurface structural features, Koeberl said, which may be deeply eroded craters or impact structures entirely covered by post-impact sediments.
“Detailed investigations involve confirmation of either shock metamorphic effects in minerals and rocks, and/or the presence of a meteoritic component in these rocks. In nature, shock metamorphic effects are uniquely characteristic of shock levels associated with hypervelocity impact,” Koeberl said.
Impact cratering is a short-time, high-energy geological event in which conditions are created that exceed conditions of nuclear bomb explosions.
These kinds of studies have led to the identification of, so far, of about 200 confirmed impact craters on Earth, Koeberl said. “Impact crater studies have actually grown in importance over the years and are an interdisciplinary effort. We encourage young researchers from all over the world to submit grant proposals,” he said.
Barringer Family Fund applications and awards are administered by The Meteoritical Society and are due by April 1.
