2015-06-03. NASA’s Hubble Finds Pluto’s Moons Tumbling in Absolute Chaos.

posted Jun 9, 2015, 5:08 PM by Alan Gould
NASA Release 15-111. For GSS A Changing Cosmos chapter 7. Excerpt: If you lived on one of Pluto’s moons, you might have a hard time determining when, or from which direction, the sun will rise each day. Comprehensive analysis of data from NASA’s Hubble Space Telescope shows that two of Pluto’s moons, Nix and Hydra, wobble unpredictably. “Hubble has provided a new view of Pluto and its moons revealing a cosmic dance with a chaotic rhythm,” said John Grunsfeld, associate administrator of NASA’s Science Mission Directorate in Washington. ...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.... http://www.nasa.gov/press-release/nasa-s-hubble-finds-pluto-s-moons-tumbling-in-absolute-chaos. See also New York Times article [http://www.nytimes.com/2015/06/04/science/space/pluto-moons-orbits-described-in-nature-article.html] with movie of the moons' motion.