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Nix and Hydra, to scale New Horizons took these photos of Nix and Hydra as it approached for its flyby; they have been resized to the same scale of about 380 meters per pixel. The two moons appear to be very close to the same size; in this image, Nix (left) measures 30 by 48 km, and Hydra measures 36 by 52 km. We may be seeing neither moon's longest or shortest dimensions, so these dimensions are consistent with the minimum and maximum dimensions measured from Hubble (26 by 56 km for Nix and 34 by 58 km for Hydra). NASA / JHUAPL / SwRI / Emily Lakdawalla