[Previous] | [Session 20] | [Next]
W. K. Hartmann (Planetary Science Institute)
Mars Global Surveyor images have allowed studies of Martian crater diameter distributions down to diameters of 16 m for the first time. A system of estimated isochrons has been developed using the (mutually consistent) Hartmann and Neukum crater production functions, and a Mars cratering rate of about twice the lunar rate. The older surfaces show complex patterns including small crater losses due to erosion/deposition effects. The youngest surfaces match the predicted isochron shapes, and include lava flow surfaces with very young ages, hundreds of My or less. It is difficult to avoid the conclusion that volcanism has been active on Mars in recent geological time.