1. Impact Craters

2. Impact Craters
Impact cratering is the dominant geologic process that alters the solid surfaces of bodies throughout the solar system.
Impact craters are approximately circular depressions in the surface of a planet, moon or other solid body in the Solar System, formed by the hypervelocity impact of a smaller body with the surface.
Barringer “Meteor” Crater, Arizona

3. Impact Cratering

4. Impact Craters Characteristics
Rim is raised compared to the surrounding terrain

5. Impact Craters
Barringer “Meteor” Crater, Arizona

6. Impact Craters Characteristics
Rim is raised compared to the surrounding terrain
Floor is lower than the surrounding terrain (Barringer Crater is over 550 ft deep)

7. Impact Craters Characteristics
Rim is raised compared to the surrounding terrain
Floor is lower than the surrounding terrain
Inverted stratigraphy

8. Impact Craters Moenkopi Kaibab Coconino
Barringer “Meteor” Crater, Arizona, looking NW

9. Impact Craters Moenkopi Kaibab Kaibab
Barringer “Meteor” Crater, Arizona, SE rim

10. Impact Craters
Moenkopi hinge. Barringer “Meteor” Crater, Arizona, NE rim

11. Impact Craters
Moenkopi hinge. Barringer “Meteor” Crater, Arizona, NE rim

12. Impact Craters Ejecta Radial ejecta surrounding a lunar crater.
Lobate ejecta surrounding a Martian crater.

13. Impact Craters Characteristics
Rim is raised compared to the surrounding terrain
Floor is lower than the surrounding terrain
Inverted stratigraphy
Ejecta
Shock metamorphism*
Shatter cones*

14. Impact Craters Shock Metamorphism in Coconino Sandstone
Unshocked Coconino Sandstone
Shocked Coconino Sandstone
Images from Traces of Catastrophe by Bevan M. French, 1998

15. Impact Craters Shatter Cones
Image Credit:
From Traces of Catastrophe by Bevan M. French, 1998, image courtesy of V.L. Sharpton

16. Impact Craters Simple Craters
Small (relatively) bowl-shaped depressions with no interior structure

17. Impact Craters Complex Craters & Basins
Complex craters have interior terraces and flat floors surrounding central peaks.
Basins are craters >300km (~190 miles) in diameter.