Moons of Pluto

Pluto has five known moons orbiting it: Charon, Styx, Nix, Kerberos, and Hydra. Little descriptions are given for these moons due to how small and similar they are.

Properties

Mass: 1.586 * 10²¹ kg

Mean Radius: 606.0 km

Semi-major Axis: 19591.4 km

Orbital Period: 247.94 years

Rotational Period: 6.38 days(synchronous)

Surface Gravity: 0.288 m/(s²)

Etymology: Charon(Ferryman from Greek myth who carried souls across the River Acheron in the Underworld)

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Charon is one of the five major moons of Pluto. Unlike Pluto, which is composed of mainly nitrogen and methane ices, Charon is dominated by less volatile water ices. The reddish-brown cap on the top of the image of Charon above, the north pole of Charon, is composed of organic macromolecules known as tholins. These are potential ingredients of life so their presence has contributed to ongoing research on the limited habitability of the moon.

Properties:

Mass: 7.5×10¹⁵ kg

Dimensions: 16 x 9 x 8 km

Semi-major Axis: 42,656 km

Orbital Period: 20.16 days

Rotational Period: 3.24 days

Etymology: Styx(River in the Underworld in Greek myth)

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Styx is the smallest known moon of Pluto, which is why its image above is extremely blurry. The complexity and strangeness behind Styx are indicative of the theorized formation of Pluto's peculiar moon system. Most scientists believe Pluto collided with another Kuiper object and its moons are debris. This would heavily explain why Styx is such a chaotically shaped and moving object in the vicinity of Pluto.

Properties:

Mass: 7.5 * 10¹⁵ kg

Dimensions: 49.8 x 33.2 x 31.1 km

Semi-major Axis: 48,694 km

Orbital Period: 24.85 days

Rotational Period: 1.829 days(chaotic)

Etymology: Nyx(Greek goddess of darkness and night)

Nix is one of Pluto's moon and interestingly is composed of water-ice, per observations, despite being spectrally neutral. The reddish hue on portions of Nix's surface indicates organic molecules along with frozen methane.

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The orbit of Nix is of course chaotic like many other Plutonian moons. This means that Nix is not tidally locked(the same side of the moon isn't facing Pluto at all times) and chaotically tumbles in its orbit.

Properties:

Mass: 1.65 * 10¹⁶ kg

Dimensions: 19 × 10 × 9 km

Semi-major Axis: 48,694 km

Orbital Period: 32.167 days

Rotational Period: 5.31 days(chaotic)

Etymology: Kerberos(Greek form of the Cerberus, a three-headed dog that protects the Underworld)

Properties:

Mass: (4.8±4.2)×10¹⁶ kg(not very exact but thus far the best confidence interval of the mass)

Dimensions: 50.9 × 36.1 × 30.9 km

Semi-major Axis: 48,694 km

Orbital Period: 32.167 days

Rotational Period: 5.31 days(chaotic)

Etymology: Hydra(Greek form of the Cerberus, a three-headed dog that protects the Underworld)

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Hydra is one of Pluto's moons. It is has a highly reflective surface due to the presence of water ice. Hydra's surface has been observed to "refresh" due to micrometeorite impacts on the surface. These impacts cause darker material within Hydra to eject continually so that the surface changes.