The Strange Dance of Pluto’s Moons

Credits: NASA/ESA/A. Feild (STScI)

NASA’s New Horizons spacecraft is still 6 weeks away from its Bastille Day flyby of former planet Pluto, but based on new data gathered by researchers using the Hubble Space Telescope,  it will have an opportunity to provide an up close view of the strange dance being called by the former 9th planet and its major moon, Charon. At least two of Plutos’s smaller moon, Nix and Hydra, wobble constantly in an unpredictable manner.

According to the NASA story:

“The moons wobble because they’re embedded in a gravitational field that shifts constantly. This shift is created by the double planet system of Pluto and Charon as they whirl about each other. Pluto and Charon are called a double planet because they share a common center of gravity located in the space between the bodies. Their variable gravitational field sends the smaller moons tumbling erratically. The effect is strengthened by the football-like, rather than spherical, shape of the moons. Scientists believe it’s likely Pluto’s other two moons, Kerberos and Styx, are in a similar situation.”