Impact Craters, evidence of bombardment by meteorites which bring rich elements from space, and some of the bigger meteorites causing mass extinction of species. On the Earth, 170-180 impact craters have been identified. They vary in size from a few hundred meters up to or more than 200 KM and range in age from recent hundred years to more than two billion years. Here are the top 5 biggest known impact craters on Earth caused by Asteroid collisions.
Vredefort Crater
Located in South Africa, Vredefort crater is the largest known impact crater on Earth- somewhere between 180-300 Km wide. But more than 2 billion years of erosion has made the exact size unknown. The Vredefort crater is a complex crater, i.e. it has an uplift rock formation at the center of the impact. As the years passed various layers of the upturned rock eroded and produced concentric patterns which are visible today.
Chicxulub crater
Located on Mexico’s Yucatan Peninsula, the Chicxulub crater is one of the largest impact craters on Earth. It is around 180 Km wide and 3000 feet deep. It eluded from detection for decades, as it was hidden beneath young rocks and sediments. Though the buried bowl can’t be seen, it has left subtle clues of its existence on the surface. Size is not only the thing that makes the crater special, it’s the evidence that a huge asteroid or comet crashed into the Earth 65 million years ago, causing the extinction of more than 70% of the species on the planet, including the dinosaurs.
Sudbury Basin
The Sudbury Crater is likely to be formed 1.8 billion years ago in the Paleoproterozoic era when a comet 10-12 Km in diameter slammed the Earth. The impact left a gigantic crater, measuring about 150 Km across, which over the years eroded to its current size forming an elliptical crater that measures about 60 Km by 30Km. NASA used the site to train the Apollo astronauts for the Moon Missions.
Manicouagan Crater
Formed about 212 million years ago, the Manicouagan crater now a lake is the best-preserved impact crater on Earth. Lake Manicouagan surrounds the central uplift of the impact structure, which is about 70 km in diameter and is composed of relatively large pieces of rock embedded ingrained material called a brecciated rock. The geographic processes have reduced the extent of the crater, with the original diameter estimated at about 100 Kms. The shock metamorphic effects are abundant in the target rocks of the crater floor.
Popigai Crater
Formed about 36 million years ago, when an asteroid sized between 5-8 Km wide battered Earth creating a crater 100 km in diameter. It is the fourth largest impact crater on Earth tying with the Manicouagan Crater. The crater is one of the most well-preserved craters in the world, having been slightly modified by geological processes. The geological observation shows that the crater has a central depression at the bottom, surrounded by a peak ring of about 45 Km wide. Popigai crater is also called the “Crater of Diamonds” because a large number of diamonds have been found, most of them being less than two millimeters in size.
