By Shreesha Ghosh
June 30, 2022
Known to be the world's largest impact by an asteroid 2 billion years ago, the Vredefort crater has a radius of about 118 miles (190 kilometres) and was declared a UNESCO World Heritage Site in 2005. It is located in Free State, South Africa. Although the crater has been eroded away, the remaining geological structures at its centre are known as the Vredefort Dome or Vredefort impact structure.
Image source: Wikipedia
The Sudbury Basin is the third-largest impact structure on Earth, with an estimated diameter of 81 miles (130 kilometres). Dating back 1.8 billion years, it is one of the oldest known impact structures in the world in Ontario, Canada. The crater was formed in the Paleoproterozoic era and is also the largest astrobleme on Earth.
Image source: NASA
This crater in Siberia, Russia, with its 100-kilometre diameter, is the joint-fourth largest verified impact crater on Earth. This collision took place around 35 million years ago. It has also been linked with the Eocene-Oligocene extinction event, which saw a floral and faunal turnover. The shock pressures from this asteroid impact instantaneously transformed the graphite in the ground into diamonds, found to this day.
Image source: Wikipedia
Manicouagan Réservoir lies within the remnant of an ancient eroded asteroid impact crater, with a multiple-ring structure about 100 km wide. Located in Quebec, Canada, the Crater was formed by an asteroid strike over 215 million years ago. It is also known as the annular Lake Manicouagan or the "eye of Quebec" that is visible from space.
Image source: Wikimedia Commons
Located in what is now Lake Acraman, a small salt lake in Gawler Ranges of South Australia, this impact structure has an estimated diameter of 56 miles (90 kilometres). It is a deeply eroded impact crater formed about 580 million years ago. The evidence for impact includes the presence of shatter cones and shocked quartz in shattered bedrock on islands within Lake Acraman.
Image source: NASA
Discovered in the early 1980s, the Chesapeake Bay Crater is located approximately 125 miles (201 kilometres) from Washington, DC and is the sixth-largest crater known on the planet. It is estimated to have been formed 35 million years ago and continued slumping of sediments over the rubble of the crater has helped shape the Chesapeake Bay. It is buried about 1500 feet below the Eastern Shore Peninsula, making it unreachable for humans!
Image source: NASA
Located on the Yucatán Peninsula in Mexico, many scientists believe that the asteroid impact that left this crater caused or contributed to the extinction of the dinosaurs. Estimates of its actual diameter range from 106 to a whopping 186 miles (170 to 300 kilometres), which could mean it is the biggest. The asteroid impact is estimated to be 65 million years ago.
Image source: NASA
Now greatly eroded, the Kara crater is a non-exposed impact structure in Russia. Some have claimed that the impact structure actually consists of two adjacent craters: the Kara and the Ust-Kara crater. Its age is estimated to be 70.3 million years old. The outcrops located on the Baydarata Gulf (Baydaratskaya) shore north-east of the crater imply that the original size could have been the fourth largest on Earth.
Image source: Wikipedia