DEBRIS DISK VARIABILITY - EXPLORING THE DIVERSE OUTCOMES OF LARGE COLLISIONS DURING THE ERAS OF OLIGARCHIC AND CHAOTICGROWTHTHE POTENTIAL TO STUDY EARTH-LIKE PLANETS IN HABITABLE ZONES HAS ELECTRIFIED THE ASTRONOMICAL COMMUNITY AS WELL AS THE GENERAL PUBLIC. NEARLY ALL OUR EFFORTS TOWARD THIS GOAL ADDRESS MATURE PLANETS DETECTED THROUGH RADIAL VELOCITY OR TRANSIT TECHNIQUES. HOWEVER NONE OF THESE EFFORTS WILL REVEAL THE STEPS BY WHICH THESE PLANETS GROW FROM EMBRYOS TO THEIR CURRENT SIZES THROUGH COLLISIONS OF OBJECTS RANGINGIN SIZE FROM ASTEROIDS TO PROTOPLANETS A PROCESS THAT LASTS FOR THE FIRST 200 MYR OF THEIR EXISTENCE. THE CRITICAL STAGES OF TERRESTRIAL PLANET FORMATION (AND IN SOME CASES DESTRUCTION) HAVE ONLY BEEN IN THE REALM OF COMPUTER SIMULATIONS. OBSERVATIONAL INPUTS TO THESESIMULATIONS HAVE UNTIL NOW BEEN LIMITED LARGELY BASED ON INDIRECT DETECTION OF PLANETS AND STATISTICAL DISTRIBUTIONS OF DEBRIS DISK INCIDENCE. HOWEVER THE NEWLY DISCOVERED VARIABLE EMISSION BY EXTREME DEBRIS DISKS (YOUNG 10-200 MYR SYSTEMS WITH FRACTIONAL DUST LUMINOSITY ON THE ORDER OF ~1%) PROVIDES A UNIQUE OPPORTUNITY TO LEARN ABOUT ASTEROID-SIZED BODIES IN YOUNG EXOPLANETARY SYSTEMS AND TO EXPLORE PLANETESIMAL COLLISIONS AND THEIR AFTERMATHS DURING THE ERA OF TERRESTRIAL PLANET BUILDING.THE FIRST SUCH SYSTEM IDENTIFIED NGC 2547-ID8 (A 35 MYR SOLAR-TYPE STAR) IS THE MOST THOROUGHLY STUDIED. DATA TAKEN BY SPITZER BETWEEN 2012 AND 2013 SHOWED A SIGNIFICANT BRIGHTENING FOLLOWED BY MONTHLY QUASI-PERIODIC VARIATIONS ON TOP OF A YEAR-LONG FLUX DECLINE. THE DISK VARIABILITY IS BEST EXPLAINED BY A LARGE IMPACT INVOLVING ASTEROIDS A FEW HUNDRED KM IN SIZE. THIS DRAMATIC EVENT PRODUCED AN OPTICALLY THICK CLOUD OF MM-SIZE DROPLETS CONDENSED FROM THE IMPACT PRODUCED VAPOR. THE SUBSEQUENT COLLISIONAL CASCADES INSIDE THE CLOUD AND THE LARGE OPTICAL DEPTH OF THE RESULTING DUST COMBINED WITH ITS ORBITAL MOTION PRODUCED COMPLEX VARIABILITY IN THE DISK OUTPUT. FURTHER MONITORING WITH SPITZER SHOWS THAT ADDITIONAL COLLISIONAL EVENTS ARE OCCURRING IN ID8. ID8 IS ONE OF A DOZEN EXTREME DISKS OBSERVED TO VARY; THIS PROPOSAL WILL FUND CONTINUED MONITORING AND ANALYSIS OF THIS ENTIRE CLASS OF OBJECT.THE ADDITION OF A TEMPORAL DIMENSION OFFERS THE POTENTIAL TO INCREASE OUR KNOWLEDGE OF FORMING PLANETARY SYSTEMS DRAMATICALLY. HOWEVER THE COMPLEX BEHAVIOR EXEMPLIFIED BY ID8 NECESSITATES GATHERING THOROUGH SETS OF DATA AND GENERATING A CAREFUL INITIAL ANALYSIS TO SUPPORT HIGH-FIDELITY THEORETICAL MODELING. WE HAVE BEEN PROVIDED WITH 130 HOURS OF WARM SPITZER CYCLE 11 TIME TO GATHER THE NECESSARY DATA FOR FOURTEEN EXTREME DEBRIS DISKS. WE PROPOSE TO ANALYZE THESE DATA TO PRODUCE (1) HIGH-QUALITY TIME-SERIES SPITZER PHOTOMETRY CHARACTERIZING THEIR DISK VARIABILITY (2) SED COLLECTION INCLUDING ALL EXISTING ARCHIVAL DATA AND PUBLISHED LITERATURE AND (3) SED MODELS TO CONSTRAIN THE DUST LOCATION AND MASS. WE WILL ALSO CARRY OUT EXPLORATORY MODELING OF THE DYNAMICS AND RE-RADIATIONOF THE DISKS GUIDED BY THESE THREE PRIMARY OUTPUTS. MORE DETAILED THEORETICAL MODELING OF THESE OBJECTS AND OTHER DEBRIS SYSTEMS IS PROPOSED SEPARATELY. IT WILL INCLUDE THE COLLISIONAL AND DYNAMICAL EVOLUTION OF AN IMPACT-PRODUCED CLOUD WITH A PROPER RADIATION TRANSFER TREATMENT. OUR LONG BASELINE MONITORING WILL SUPPORT THE DETAILED ANALYSIS OF THE PLANET CONSTRUCTION STEPS TRACED BY DUST IN THE TERRESTRIAL ZONE. IT WILL ALSO BUILD THE FOUNDATION FOR MEASUREMENTS WITH JWST.