Where can we see meteorite craters in North America?

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Dear Dave,
This winter an asteroid missed the Earth by a fairly close margin, and a meteorite swooshed across the sky in Siberia, leaving some fragments but no crater. Those events got the family all excited. We have decided that we would like to visit meteorite craters when we take our family vacation this summer. We have heard of the Meteor Crater in northern Arizona. Are there others in the US or Canada to put on our list?
Jeannette Blankenship, Sioux Falls, South Dakota

Dear Jeannette,

Artist's depiction of a very large meteorite strike. NASA

Great topic. There are many other meteorite craters. But, most are very old and deeply eroded, so they are not very obvious form the ground, or even from the air. Many have been detected using gravity studies (that's a whole different topic!). Meteorite craters are called 'astroblemes'- an obscure but logical term when you think about it for a couple of minutes. To be sure we are all using the correct terms, a 'meteor' becomes a 'meteorite' when it impacts the earth. Not all meteorites come from the asteroids, some are known from Mars and the Moon.

The Barringer Crater in northern Arizona. For scale note the road snaking in at upper right. This photos is from NASA.

'Meteor Crater' (known to science as the 'Barringer Crater' after the discoverer) in northern Arizona is the best known, and the most accessible for your family. The crater is 3/4 mile across and 575 feet deep. It was formed 49,000 years ago when a nickel-iron meteorite weighing around 300,000 tons and 150 feet across hit the earth at a velocity of 28,600 mph. (You may find higher velocities cited on the internet, but this one is from the latest published scientific calculations).

Probably the next best from a spectator's perspective in North America is Upheaval Dome (this link gets you to some great photos) in Canyonlands National Park, near Moab, Utah. This circular structure does not look like a crater. The layered rocks that make up the local bedrock are deformed into a circular structure 1.7 miles across. For years, many geologists thought it could be caused by a dome of salt rising upward and displacing the strata,21 but recent geologic study shows that it is almost certainly the result of an impact around 170 million years ago.

There are others, but they are pretty obscure. Find a map of North American impact craters at the website of the Planetary and Space Science Centre, University of New Brunswick. If you use Google Earth, the PaSSC. An impact site map at Geology.com let's you learn more about 50 of these impact sites around the world. And this website has a .kml file you can download into Google Earth that shows the location in great detail of known and suspected craters all over the world.

So, have a great summer trip, Jeannette!

Dr. Rock