A fragmented comet crashed into Earth’s atmosphere 12,800 years ago, causing … [+]
Scientists have found evidence for the so-called Younger Dryas impact hypothesis that a comet exploded in Earth’s atmosphere 12,800 years ago, causing Earth’s temperature to drop.
A piece of paper published in the magazine Aerial explosions and craters reveals hints of an ancient cosmic explosion at three separate sites in New Jersey, Maryland and South Carolina. The evidence includes platinum, molten glass and shock-fractured quartz, all suggesting the kinds of forces and high temperatures associated with “airburst” comets.
This is similar to what happens during atomic explosions near the Earth’s surface.
“Touchdown” air blasts.
Although massive asteroids and comets hit the Earth, causing craters, most explode in the air as fireballs or airbursts. “What we found is that the pressures and temperatures were not characteristic of large impactors that form craters, but were consistent with so-called ‘touchdown’ air bursts that do not form much relative to craters.” he said James Kennett, professor emeritus at the University of California, Santa Barbara.
It is thought that the burn caused by the comet’s explosion may have also killed megafauna in North America, such as mammoths and giant ground sloths.
Thousands of Pieces
During the event, a comet about 62 miles (100 km) wide probably fragmented into thousands of pieces. This would explain the sediment layer over much of the northern hemisphere containing impact-related materials such as iridium, platinum, molten glass and nanodiamonds.
Similar broken quartz grains and molten glass have been found at the Trinity atomic bomb test site in New Mexico, where a 20-kiloton bomb was detonated in July 1945 in a 100-foot (30.5 m) tower.
This part of Siberia was hit by a meteorite fall on July 30, 1908 in what was called … [+]
Tunguska event
One of the most famous cosmic explosions was the so-called “Tunguska Event” of 1908, when a shock wave from a 40-meter-long asteroid or comet fragment exploded about six miles (120 kilometers) above Siberia. It destroyed 830 square miles (2,150 square kilometers) of forest.
This is not the only comet impact that is believed to have significantly affected Earth’s climate and biodiversity. An asteroid or comet is known to have hit Earth near Mexico’s Yucatan Peninsula 66 million years ago, causing a 110-mile (180-km) wide crater. Chicxulub Crater. The strike is thought to have caused a decades-long impact winter that killed the dinosaurs.
Cosmic Companion
In 2022, scientists announced that they had found a suspected second asteroid impact crater of a similar age under the North Atlantic Ocean off Guinea, West Africa, five miles (nine kilometers) wide. It suggests that the space rock that killed the dinosaurs may have had a smaller cosmic companion or was part of a cluster.
Only 200 impact craters have so far been discovered on the Earth’s surface – about a tenth of them at the bottom of the sea – despite the impact of asteroids throughout its existence.
I wish you clear skies and open eyes.
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