Investigating Photometric Properties of Pluto’s Surface

Abstract:

The New Horizons mission revealed that Pluto is a geologically active world with a multitude of diverse surface morphologies. Herein, we focus on photometric modeling to quantitatively investigate the physical properties of these varied morphologies. Using observations from the New Horizons Multispectral Visual and Infrared Camera (MVIC), we produced phase curves of Pluto's surface features at red, blue, and NIR wavelengths. We identified areas of Pluto with the best phase coverage by binning the MVIC data into 10 deg² boxes and selecting boxes with appropriate observational geometries. We then produced phase curves for the surface morphologies that had the widest range of phase angle coverage (16° - 170°). This allowed us to investigate phase curves from many representative features on Pluto, including Sputnik Planitia, Cthulhu Regio, Hayabusa Terra, etc. Preliminary fits to Hapke photometric models display physically significant differences in single scattering albedo and roughness for the different morphologies investigated. Through this photometric modeling process, we will learn new details of Pluto’s surface composition and ongoing processes, which lends itself to further comparative planetology with other Kuiper Belt Objects, including Neptune’s moon Triton.