Physical Aveiro explain chaotic rotation of Pluto’s moons – Daily News – Lisbon

Physicists at the University of Aveiro found an explanation for the “chaotic rotation” of four of Pluto’s moons, discovered two months ago by US scientists. The influence of another moon of the dwarf planet, Charon, which is almost as large as Pluto, let the “indecisive,” explains the article published in the latest issue of the scientific journal “Astronomy & amp; Astrophysics Letters.”

In June, an investigation conducted by scientists Mark Showalter (SETI Institute) and Doug Hamilton (University of Maryland), United States, revealed that the rotation of Nix moons, Hydra, Cerberus and Styx is not constant and varies unpredictably over time, unlike what happens with moons discovered so far of most planets.

Now, an international team led by Physics Department of the University of Aveiro has focused on the “strange rotation “of the four moons of Pluto and found the reason for applying the laws of physics.

The Nix moons and Hydra
       Photograph © NASA / JHUAPL / SWRI

According to Alexandre Correia, coordinator of the research, two factors distinguish those little four moons of all others, including Charon, the other moon of Pluto which has a regular rotation. “Due to the four moons concerned are small bodies with diameters of less than 50 kilometers, they resemble more asteroides potato-shaped than spherical bodies such as the moon Earth and always have therefore a more elongated shaft “he said.

Another of the factors that make Nix, Hydra, Cerberus and Styx a single set in the solar system, says the expert in solar systems, extrasolar planets and planetary physics,” is that, unlike four small moons, the largest moon of Pluto, Charon, is almost as large as Pluto, so, technically, the Pluto-Charon system should be classified as a binary system [system with two similar-sized bodies orbiting around the center common mass] and not planet-moon system. “

” If Charon did not exist, the small moons would evolve by tidal effect until synchronous with Pluto, as expected, and if only existed Charon, small moons would point out the major axis in Charon’s direction to also become synchronous with this celestial body “, explains.

what goes O, according to the researcher, is that as there is Pluto and Charon, “small moons are ‘undecided’ and some times tend to point the major axis to Pluto, sometimes for Charon, depending on who went closest” and this alternation results in an uneven rotation of the small moons because they never can get to be synchronous or Pluto or Charon with “.