Pluto’s Moons Tumbling in Absolute Chaos

[Waspie_Dwarf]

NASA’s Hubble Finds Pluto’s Moons Tumbling in Absolute Chaos

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. “When the New Horizons spacecraft flies through the Pluto system in July we’ll get a chance to see what these moons look like up close and personal.”

Read more...

[Waspie_Dwarf]

Numerical Simulation of Nix's Rotation

This is a numerical simulation of the orientation of Nix as seen from the center of the Pluto system. It has been sped up so that one orbit of Nix around Pluto takes 2 seconds instead of 25 days. Large wobbles are visible, and occasionally the pole flips over. This tumbling behavior meets the formal definition of chaos; the orientation of Nix is fundamentally unpredictable.

Credit: STScI and Mark Showalter, SETI Institute

Source: NASA.gov Video

[+OverSword]

That video seems impossible.

[Zalmoxis]

It's because it's oblong, isn't it?

[Waspie_Dwarf]

It's because it's oblong, isn't it?

It's elongated shape is only part of the reason.

If you read the article it actually tells you why this happens:

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.

[paperdyer]

Waspie - I always thought something needs mass to have a gravitational field. Does this mean Pluto and Charon wanted to be a single planet and some outside gravitation force kept/keeps this from happening?

[Buzz_Light_Year]

Planet X/Nibiru gravitational field effect.

What else could it be? /sarcasm

Edited June 4, 2015 by Buzz_Light_Year

[Rlyeh]

Waspie - I always thought something needs mass to have a gravitational field. Does this mean Pluto and Charon wanted to be a single planet and some outside gravitation force kept/keeps this from happening?

No, it means their barycenter is some distance above Pluto's surface.

http://spaceplace.nasa.gov/barycenter/en/

[Waspie_Dwarf]

Waspie - I always thought something needs mass to have a gravitational field.

It does. The gravitational field affecting Nix and Hydra is generated by Pluto and Charon.

Does this mean Pluto and Charon wanted to be a single planet and some outside gravitation force kept/keeps this from happening?

Rlyeh is correct with his comment about the barycentre, but let me explain further.

When objects are in orbit around each other they orbit around their combined centre of gravity, this is the barycentre. Think of a stick with two weights on it, if one weight is much heavier than the other then the centre of gravity will be closer to the heavier weight. The same thing happens with planets and moons. In most cases one object will be so much more massive than the other that the barycentre actually lies within the larger body. This is the case with the Earth and the moon and with all the other planets in the solar system. It is not, however, the case with Pluto/Charon. Charon is sufficiently massive in relation to Pluto that the barycentre lies in the space between the two worlds. Take a look at the "]video in this thread showing Pluto and Charon orbiting around the barycentre. You can clearly see Pluto "wobble".

In most cases the fact that all the moons are orbiting around the much larger planet leads to stability. Nix and Hydra, on the other, are orbiting aroung a piece of empty space. Pluto and Charon are also orbiting around this piece of empty space. The constant gravitational pushing and pulling of Pluto and Charon are what are causing the instability and therefore the chaotic spin of these tiny moons.

[schizoid78]

New Horizon is less than 2 months reaching Pluto.

Hopefully this spaceship (the fastest ever made) is going to give us better measurement.

S

[McFakename]

Poor Pluto.... first he's downsized then he's classified as unstable.

[Robert1]

This is a very interesting article. I always liked Pluto as a planet. Despite the fact that it was demoted to dwarf planet( as if Pluto did something wrong). Maybe the New Horizons probe will change that.