0 Assigned ID: 165 ----- Attempting Submission 1 (Wed Apr 06 20:40:58 GMT 2016) ----- HST Phase I Proposal 165 (dustscat.apt) successfully submitted. Receipt: # 165-1 ----- Attempting Submission 2 (Thu Apr 07 21:18:23 GMT 2016) ----- HST Phase I Proposal 165 (dustscat.apt) successfully submitted. Receipt: # 165-2 ----- Attempting Submission 3 (Fri Apr 08 13:45:14 GMT 2016) ----- HST Phase I Proposal 165 (dustscat.apt) successfully submitted. Receipt: # 165-3 ----- Attempting Submission 4 (Fri Apr 08 21:29:07 GMT 2016) ----- HST Phase I Proposal 165 (dustscat.apt) successfully submitted. Receipt: # 165-4 ----- Attempting Submission 5 (Fri Apr 08 21:32:03 GMT 2016) ----- We propose realistic modeling of scattering of light by small aggregate dust grains that will enable us to interpret visible to near-infrared imaging of debris disks. We will determine if disk colors, phase functions, and polarizations place unique constraints on the composition of debris dust. Ongoing collisions of planetesimals generate dust; therefore, the dust provides unique information on compositions of the parent bodies. These exosolar analogs of asteroids and comets can bear clues to the history of a planetary system including migration and thermal processing. Because directly imaged debris disks are cold, they have no solid state emission features. Grain scattering properties as a function of wavelength are our only tool to reveal their compositions. Solar system interplanetary dust particles are fluffy aggregates, but most previous work on debris disk composition relied on Mie theory, i.e. assumed compact spherical grains. Mie calculations do not reproduce the observed colors and phase functions observed from debris disks. The few more complex calculations that exist do not explore the range of compositions and sizes relevant to debris disk dust. In particular, we expect porosity to help distinguish between cometary-like parent bodies, which are fluffy due to high volatile content and low collisional velocities, and asteroidal-like parent bodies that are compacted. Extrasolar Planets and Planet Formation 0 Regular false false true SUPPORTED