Comet Dust Composition and Astrophysical Connections

Solar system formation is an engine that simultaneously preserves and transforms interstellar medium (ISM) dust grains into planetesimals. In our Solar System, comets are some of the best preserved relics from that epoch. If comets are a mixture of ISM dust and solar nebula processed material, they would allow us to investigate both the inputs and outputs of dust transformation in the young Solar System. If instead, ISM dust is completely processed in the disk, comets would more directly reflect the diversity of the dust forming processes and environment. Whichever the case, the diversity of dust within comet nuclei and throughout the whole population, can be used to test dust formation and transportation, and comet migration scenarios. We are surveying the dust properties of comets through mid-infrared spectroscopy. In this talk, I review the known properties of comet dust, the current status of our survey, and our observations of particular comets, including comet C/2012 S1 (ISON), observed with SOFIA+FORCAST.