|Gosses Bluff impact crater|
in Northern Territory, Australia
The earth has about 180 identified impact craters. In contrast, the remains of thousands of impact craters are visible on the moon.
The moon's surface is comparatively static, while earth's surface is an ever-changing system with plate tectonics, mountain formation, and erosion.
Over geological time, most of earth's impact craters are:
- Eroded away;
- Obliterated by mountain building;
- Buried by younger deposits; or
- Inundated by oceans and fresh water.
|Greenland's Maniitsoq Crater|
Discovery in Greenland
The remains of a 3000 million year-old meteorite impact was discovered on the western coast of Greenland in 2009 by a GEUS geologist. The crater impact structure found near the town of Maniitsoq is about 310 miles wide.
Until the discovery of the Maniitsoq impact crater, the 2020 million year-old, 186 miles wide Vredefort crater in South Africa was believed to be earth's oldest (and largest) impact structure.
The oldest identified impact craters are shown in the table below:
|Amelia Creek||Northern Territory, AU||12||1660-600|
|Shoemaker||Western Territory, AU||19||1630|
|Strangways||Northern Territory, AU||16||646|
|Beaverhead||Idaho / Montana, US||37||600|
Facts which at first seem improbable will, even on scant explanation, drop the cloak which has hidden them and stand forth in naked and simple beauty.References
~ Galileo Galilei
- The remains of a gigantic, three-billion-year-old meteorite impact discovered in Greenland, June 28, 2012, GEUS.
- Geological Survey of Denmark and Greenland - GEUS.
- List of impact craters on Earth, Wikipedia.
- Earth Impact Database, Wikipedia.
- Pictures of The Biggest Impact Craters on Earth.