Styx (moon)

Pluto moon P5 discovery with moons' orbits

Styx is a small natural satellite orbiting Pluto. Discovered in 2012 by a team led by astronomer Mark R. Showalter, using images from the Hubble Space Telescope, Styx was announced to the public on July 11, 2012. It is the fifth moon of Pluto to be discovered, following Charon, Nix, Hydra, and Kerberos. The discovery of Styx was part of a search for potential hazards to the New Horizons spacecraft, which flew by Pluto in July 2015.

Discovery and Naming

The discovery of Styx was announced by the International Astronomical Union (IAU) on July 11, 2012. The moon was identified in images taken by the Hubble Space Telescope's Wide Field Camera 3 on June 26, 2012. Following its discovery, Styx was temporarily designated S/2012 (134340) 1. The name "Styx" was officially adopted by the IAU in 2013, continuing the tradition of naming Pluto's moons after figures associated with the underworld in classical mythology. In Greek mythology, Styx is the river that separates the world of the living from the realm of the dead.

Physical Characteristics

Styx is the smallest and outermost of Pluto's known moons, with an estimated diameter of about 10 to 25 kilometers. Due to its small size and distant orbit, detailed characteristics such as its composition and surface features remain largely unknown. Observations suggest that, like Pluto's other moons, Styx is likely composed primarily of water ice and rock.

Orbit

Styx orbits Pluto at a distance of approximately 42,000 kilometers, making it the second-farthest moon from Pluto, after Kerberos. Its orbit is nearly circular and is coplanar with the orbits of Pluto's other moons, suggesting a common origin. The orbital period of Styx is about 20.2 days. The resonant relationships among Pluto's moons, including Styx, are of interest to astronomers studying the dynamical evolution of this satellite system.

Exploration

As of the last update, Styx has not been directly explored by any spacecraft. The closest approach to Styx was made by NASA's New Horizons spacecraft during its flyby of the Pluto system in July 2015. However, due to the small size of Styx and the speed of the flyby, the images and data obtained were limited in detail.

Significance

The discovery of Styx, along with Pluto's other small moons, has provided valuable insights into the complex gravitational interactions within the Pluto system and the formation and evolution of Kuiper Belt objects. The moons' orbits and physical properties offer clues to their origins, possibly as fragments from a collision or as captured bodies from the Kuiper Belt.