The Clearest View Yet of Pluto's Two Tiny Moons

NASA's New Horizons Spacecraft was launched to give us the first close-up view of Pluto, and it's delivering. This footage shows the best-ever view of two of its tiny moons—one of which never been seen before.


The two moons, Nix and Hydra, are visible in a series of images acquired by New Horizons between January 27th and February 8th. Those images are assembled into a seven-frame movie here, so you can see the moons orbit Pluto. Hydra sits in the yellow diamond, Nix in the orange. This is the first time Nix has ever been caught on film.

In the images on the left, Nix and Hydra are only barely visible through the glare of Pluto, its main moon Charon, and plenty of stars. On the right, the images are processed to remove much of the bright light. In turn, that produces image artefacts, including bright spots that aren't real features, but it does make it much easier to see the two moons. (If you'e wondering, the bright and dark streaks are an artefact of the camera electronics, a result of overexposure of Pluto and Charon.)

The existence of Nix and Hydra was first identified, by the team that put New Horizons into space, within Hubble Space Telescope images back in 2005. Hydra orbits Pluto every 38 days at a distance of approximately 40,200 miles; Nix orbits every 25 days at a distance of 30,260 miles. The moons are small—-between 25 and 100 miles in diameter. We'll have a better idea of their size as New Horizons gets closer to them.

Indeed, these are some of the first images in a series of long-exposure images that we'll continue to see from New Horizons through until early March—so expect more interesting results in the coming month. [NASA]

Image by NASA/Johns Hopkins APL/Southwest Research Institute



To be pedantic, Nix still hasn't been caught on film. It's been caught on CCD, or CMOS.