Planetary Sciences News

Pluto's Moons Nix and Hydra Show Their Faces

When the New Horizons spacecraft photographed Pluto last week, it snapped the most revealing images yet of two little-known moons of the dwarf planet.

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Pluto’s moons Hydra and Nix appear in unprecedented sharpness in images released today from NASA’s New Horizons mission. For the first time, scientists are also able to estimate the sizes of these tiny natural satellites: Nix (left) at 26 miles (42 kilometers) by 22 miles (36 kilometers) and Hydra (right), 34 miles (55 kilometers) by 25 miles (40 kilometers).

Nix’s new portrait, imaged in enhanced colors, shows a reddish patch reminiscent of a bull’s-eye. In a press release, scientists said that they suspect the region could be an impact crater on the jelly bean-shaped moon but are awaiting additional data from the spacecraft to better understand what they’ve observed.

The New Horizons spacecraft captured these images on 14 July while 102,000 miles (165,000 kilometers) from Nix and 143,000 miles (231,000 kilometers) from Hydra. Nix and Hydra’s debut comes on the heels of other detailed images of Pluto, taken during the spacecraft’s historic Pluto flyby.

—JoAnna Wendel, Staff Writer

Citation: Wendel, J. (2015), Pluto’s moons Nix and Hydra show their faces, Eos, 96, doi:10.1029/2015EO033119. Published on 21 July 2015.

© 2015. The authors. CC BY-NC 3.0