FORCAST Observations of Comet C/2012 K1 (Panstarrs)

Comet dust provides a window to the early evolution of our Solar System, and its composition can constrain dust formation and mixing processess extant in our proto-planetary disk. Comet C/2012 K1 (PanStarrs), a dynamically new (1/a < 1e-4) Oort Cloud comet, is predicted to reach a [V] of 7 mag or less in 2014 Apr-May passing within 1.7 AU of the Earth (pre-perihelion). As a "new" comet (first inner solar system passage), the coma grain population is expected to be extremely pristine, unencumbered by a rime and insufficiently irradiated by the Sun to carbonize its surface organics. We propose SOFIA (+FORCAST) grism observations to obtain 8 to 27.7 micron spectra to enable derivation of the coma grain properties. The region from 9 to 12 micron contains features from amorphous and crystalline silicates (e.g., 11.2 micron) while 17.6 to 27.7 micron covers discrete resonances from crystalline silicates key to ascertaining the shape of the crystals and their condensation T(K) within our protoplanetary disk by comparison to model and lab data and contains potential spectra signatures providing new clues as to whether organics, including carbonates and phyilosilicates, are extant in comets. "Snap-shot" images of the comet two wavelengths will detect coma structures like jets, linking these morphologies to grain properties (derived from color temperature maps).