The closeups of Nix and Hydra were captured by the first ever flyby of Pluto and its moons by the New Horizons spacecraft last week and released by NASA today.
Hydra, Pluto’s most distant moon, has a highly irregular shape, and is about 40 km wide and 55 km long.
Nix is a jelly bean-shaped moon about 42 km long and 36 km wide. The enhanced color image shows a reddish region with “hints of a bull’s eye pattern” that scientists suspect to be a crater. New Horizons snapped the Nix photo from a distance of about 165,000 km.
“Additional compositional data has already been taken of Nix but is not yet downlinked. It will tell us why this region is redder than its surroundings,” New Horizons mission scientist Carly Howett, of the Southwest Research Institute in Boulder, Colorado, said.
“This observation is so tantalizing, I’m finding it hard to be patient for more Nix data to be downlinked,” she added.
The Hydra image shows two apparent craters, and suggests that the upper and lower portions of the moon may be made of different stuff, at least on the surface.
“Before last week, Hydra was just a faint point of light, so it’s a surreal experience to see it become an actual place, as we see its shape, and spot recognizable features on its surface for the first time,” mission science collaborator Ted Stryk, of Roane State Community College in Tennessee, said in the same statement.
Pluto’s other known moons are Charon, Kerberos and Styx.