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View Full Version : Neptune Kidnapped Triton from Another Planet



Fraser
2006-May-12, 12:04 AM
SUMMARY: Neptune's moon Triton is unique in the Solar System because it's the only large moon that orbits in the opposite direction to its planet's rotation. Researchers have developed a computer model that explains how Neptune could have captured Triton from another planet during a close approach. Under this scenario, Triton was originally part of a binary system with another planet. They got too close to Neptune and Triton was torn away.

View full article (http://www.universetoday.com/am/publish/neptune_oddball_triton.html)
What do you think about this story? post your comments below.

Jerry
2006-May-12, 02:25 PM
Well...there are a lot of odd-ball moons in the solar system: Io, Titan, Phoebe, Enceladus...and a lot of unexpected stuff showing up in comet nuclei. It would be better if they had stated this is a 'possible', rather than a 'likely' scenario - it is just a guess.


There are a lot of reasons emerging for viewing the standard model of the solar system development with a skeptical eye...and there is much to learn.

diskmaster
2006-May-12, 06:12 PM
I have a question. When will they list which planet it was captured from.

diskmaster:confused:

Ilya
2006-May-12, 06:46 PM
I have a question. When will they list which planet it was captured from.

diskmaster:confused:
The planet Triton was captured from almost certainly is no longer in the Solar System. It had to be on an eccentric orbit to begin with -- crossing orbit of Neptune, -- and such close encounter would likely throw it out of the Solar System entirely. At best, it is now a Kuiper Belt object.

Note that according to the article, Triton was not originally a "moon of a planet" (implying something relatively small orbiting something much larger). Rather, it was one half of a "binary object" -- Triton's companion being not much bigger than Triton itself.

altizar
2006-May-12, 07:57 PM
It's a nice workable theory. They just need to gather some more empircal data on the existance of binary objects with objects of that same relative size. From the numbers they where posting it sounds like there are not a lot of binary objects in the kuiper-belt that come close to the mass involved with Triton.

Ray Bingham
2006-May-13, 04:11 PM
Interesting article primarily in that he begins with the uniqueness of Triton in its retrograde movement and then lists many other bodies that move in retrograde orbit. Justified with the note that it is "the largest" . Well it may be the "largest" but if it is not the "only" Its not that unique.

He also makes a big deal about the Pluto, Charron system being a dual body system but never making any coment about the Earth, Moon system which is very much in the same class of dual body systems.

Would also liked to have seen something regarding the rotation of Triton. Is it retrograde too or does it rotate the same as all the rest. How would that relate to its having been captured.

Also i seem to have missed something about why it is easier to capture one of a dual body system rather than bodies that orbit farther apart where the effect of gravitational attraction would of course be less.

someday I'm gonna get me one of those cool names you all use.

Ray Bingham

Ilya
2006-May-14, 11:51 PM
He also makes a big deal about the Pluto, Charron system being a dual body system but never making any coment about the Earth, Moon system which is very much in the same class of dual body systems.

Depends on the definition. Charon is 1/10 the mass of Pluto; Moon is only 1/80 the mass of Earth. Some would say Earth-Moon system is "in a different class".


Would also liked to have seen something regarding the rotation of Triton. Is it retrograde too or does it rotate the same as all the rest. How would that relate to its having been captured.

Triton is tidally locked to Neptune, so yes, its axial rotation is also retrograde. Not that it means much -- Triton's rotation would end up that way within a few tens of megayears no matter how it started out.

Jerry
2006-May-15, 04:44 PM
...

Also i seem to have missed something about why it is easier to capture one of a dual body system rather than bodies that orbit farther apart where the effect of gravitational attraction would of course be less.

Ray Bingham
Good Observations, Ray. It would be much easier to capture one member of a binary pair than a single object: Any moon captured by a larger object (should) originally be in a highly elliptical orbit, and using standard Newtonian mechanics it is difficult to reduce this to a 'much rounder' ellipse. If Neptune passed between two rogue binary objects, it would be a lot like the neck of an osterich caught between one of those pairs of ball-thingys (that is a technical term...bolos?) used for hunting, and one of orbits could then be circularized by the temporary combined pull of Newton and the partner, before the partner flys off into never land.

The strength of their argument is that it provides a method for taking most of the elliptic out of an elliptical orbit. Emily has pointed out in her Planetary blog that this argument works for all of the odd moons in odd-ball orbits, not just the biggest one. In fact it works for moons in general.