Circumstellar disks experience episodes of heightened collisional activity long after 
planets are expected to have formed. The Late Heavy Bombardment, which occurred ~700 Myr 
after the formation of the planets, represents just such a period of heightened activity in 
our solar system. We have initiated a mid-infrared observational program to explore the role 
played by these dust-producing events in debris disks. The disks in our sample are 
associated with stars that are much older than the expected lifetimes for primordial dust 
loss, so the observed dust must be resupplied through collisions of planetesimals or by 
cometary ejecta. While many debris disks have been photometrically detected, very few have 
been imaged to determine the actual distribution of dust in the disk.

We give a progress report on our ongoing mid-infrared observational study of debris disks 
candidates that we are imaging with T-ReCS at Gemini South and Michelle at Gemini North. Our 
high angular resolution (~0.5") images of the thermally emitting dust in these disks 
constrain the location of the replenished dust. Our current sample of 20 disks includes that 
associated with the star Zeta Lep. We have resolved Zeta Lep?s disk for the first time and 
shown it to be the size of our asteroid belt and therefore possibly the archetype for a new 
class of debris disk. We also present and discuss our images of another disk recently 
discovered and resolved by others at shorter wavelengths and that bears many intriguing 
similarities to the Beta Pic disk.  Through modeling the disk morphologies, we may be able 
to set limits on the dominant physical processes responsible for the observed dust 
distribution.