Touring Earth’s Impact Craters

Wednesday, 17th March 2010 by

Looking up at the moon, one of the most striking visible features has to be the sheer number of impact craters around its surface. These giant holes in the ground are made by asteroids and comets flying through space and then crashing into our little satellite.

Of course many of these are easy to see without any special equipment, so for many years scientists on Earth wondered if we can see them all so easy up there, why can't we see them down here on our planet? Then along came aerial photography…

GSS visited some of the most recognizable impact craters on Earth already, including Barringer Meteor Crater in the United States and Manicouagan Impact Crater in Canada, but updated and enhanced imagery makes these sites worth a second visit.

Barringer Meteor Crater Manicouagan Impact Crater

We start our tour with the largest verified impact crater on Earth, Vredefort Crater in South Africa. Measuring a staggering 250 - 300 km (155 - 186 miles) across, this crater was formed over 2 billion years ago by an asteroid estimated 10 km (6 miles) in size.

Today, the most recognizable feature of the crater is the northwest rim that created the mountains near the town of Parys. Vredefort was also added to the list of UNESCO World Heritage Sites in 2005.

Vredefort Crater Vredefort Crater Outline

Our next stop is a crater in Northern Ontario, Canada near the city of Sudbury. The Sudbury Basin was formed by a meteorite impact 1.85 billion years ago, creating a round 250-km (155 miles) crater.

Subsequent geological processes like tectonic plate movement then stretched into its current oval shape, which is hard to see on the satellite image. However, the crater shape is strikingly obvious when using Google's terrain mapping. It is the second largest verified impact site on the planet.

Sudbury Basin Sudbury Basin Terrain

Perhaps the most famous meteorite impact of them all is the one that slammed the Earth in the Yucatán Peninsula of Mexico, and also is the one that scientists believed killed 75% of the species on Earth including the dinosaurs1.

About 65 million years ago, a 10 km (6 mi) wide meteorite slammed into the Earth and created a 180 km (110 mi) wide crater centered just off the coast of present day Mexico in the Gulf of Mexico. Today, the south to southeast rim can still seen with Google's satellite maps if you know where to look. The Chicxulub crater is the third largest verified impact crater on the planet.

Chicxulub Crater Chicxulub Crater Outline

Be sure to check out the other GSS articles on impact craters and other natural landmarks, including the Kebira Crater. Check Wikipedia for more information about the Vredefort Crater, Sudbury Basin, or the Chicxulub Crater. Since there are so many sites around the Earth, we'll be sure to have more crater articles soon!

  1. Although the debate rages on about what caused the extinction of the dinosaurs, the astroid impact theory was recently deemed the most likely↩︎