The student dust counter: Status report at 23 AU

The Student Dust Counter (SDC) is an impact dust detector on board the New Horizons Mission to Pluto. SDC was designed to resolve the mass of dust grains in the range of 10^-12 < m < 10^-9 g, covering an approximate size range of 0.5-10 μm in particle radius. The measurements can be directly compared to the prediction of a grain trajectory tracing model of dust originating from Edgeworth-Kuiper Belt (EKB). Comparing our measurements and model prediction is used to estimate the net mass production rate and the ejecta mass distribution power law exponent to be M = (8.9 ± 0.5) x 10⁵ g/s and α = 3.02 ± 0.04, respectively. Through April 2012, the New Horizons spacecraft reached approximately 23 AU, enabling SDC to map the dust density distribution along its path.