Pluto chapter III

[mrgizmo65]

Paul,because of Pluto's odity I agree it had a strange begining and for sure by being influenced by varying gravitational fields things will change. Is it too far out of considering the possibility of Pluto being captured in an orbit around Neptune?? That would be something to talk about. A former planet becoming a moon of another planet???

[Paul D]

Jerry,

Pluto's orbit does cross Neptune's as seen here http://1.bp.blogspot.com/-CuIGJ6xXKKo/T ... -orbit.jpg so the possibility of Neptune destroying or capturing Pluto is a possibility.

Just like earth, we have objects pass in between us and the moon but we don't capture or destroy it. With all planets the object must enter the "keyhole" zone of the planet. For the giants this is a bigger window but for earth its much smaller. Pluto may never enter Neptune's keyhole zone but if and when it does Pluto will be affected.

Bruce, you said they had to have come close in billions of years, well I counter and say in billions of years they never collided so, close yes. Just not close enough.

[mark.m]

Wikipedia has some interesting information on the stability of the solar system, including Pluto and Neptune, which are currently locked in an orbital resonance that prevents collisions for some time into the future (10-20 million years). Beyond that, we can't predict.

By the way, one of the things mentioned in that article is that there's a 1-2% chance of a collision between Mercury and Earth 3-4 billion years from now, as a result of a future resonance between Mercury and Jupiter. I can see it now: "Coming soon to a theater near you . . ."

- Mark

[mrgizmo65]

Mark,many thank for joining the discussion.I find it refreshing to hear the opinions of all.It makes for having interesting coversation and perhaps a new idea concerning..Pluto's odd orbit. I'm sure there are many theories of how this came to be. Can any of you mention some of them??? I am asking because I don't know,and appreceate the input,it helps making the cold weather and the less than good viewing nights Jerry

[mark.m]

..Pluto's odd orbit. I'm sure there are many theories of how this came to be. Can any of you mention some of them???

Jerry - Thanks for your comments. I'm finding this conversation kind of fun. (The one course in college that I received the lowest final grade on was Dynamical Astrophysics: the study of orbits. This conversation is reminding me that I may actually have learned something from that course.)

What I've read is that some researchers have shown through simulations that Neptune played a big role in shaping the outer solar system. It probably started much closer to the sun than it is now, and slowly grabbed small stuff just beyond its own orbit. Each time that happened, the small stuff would either get thrown in to the inner solar system, or get "locked" in a resonance orbit with Neptune. In the process, energy would be transferred from Neptune to the little guy, and Neptune's orbit would creep out a little bit into a bigger, lower-energy orbit. That, in turn, would give Neptune some new little stuff to play with, which would either get tossed toward the center or locked up with Neptune. Each time Neptune encountered something new, it had the potential to have a significant effect on all the little stuff that was locked in resonance. This is probably what nudged Pluto into its inclined orbital plane and pushed it from a circular orbit to something more elliptical.

There's another interesting article here that talks about the dance of the four big planets. That article describes the move outwards by Neptune as more of a "jump" than a "creep", triggered by a transient resonance between Jupiter and Saturn that destabilized a lot of the planets' orbits.

- Mark

[AndyG]

Mark, Great explanation, and thanks for those article links, I just learned a lot.

[NGC7000]

Interesting insights, Mark.

Tom

[mrgizmo65]

Thank you again for your input. I have just recently read a about those different things that influence the orbits of planets stars and other astronomical objects. In the particular interest was those things that affects the moon and it's orbit. In this case the. concept is that photons reflected from the earth are creating a reactionary force which in due time will make the moon spiral out away from earth. For Alli know is just evolution

[mrgizmo65]

One thing in the material I read that I found interesting, even though I don't have a full understand is Bode's law.From what I could understand about it it is a mathematical equation from what I take of it explains the distribution of planets in the solar system.Going by that equation, it predicted the presence of one planet. I believe it was Saturn. If any one would care to elaborate, l'msure there would be more than one person to listen. Jerry

[Pete]

Bode's law is probably a function of harmonics. It is only approximate and I suspect that it wasn't calculated, but simply concocted to describe what is. As such it would be better labeled Bode's descriptor.

The Night Sky Network has a cash register tape Scale of the Universe demo that I use in my classes. You strip off about 6' of tape and draw a tiny dot at one end and a 1/2" circle at the other. Label them Pluto and Sun respectively. Fold the paper in half, and at the fold draw a small circle and label it Neptune. Fold the paper in half between Neptune and Sun and on the crease draw/label Uranus. Fold the paper in half between Uranus and Sun and on the fold label/mark Saturn. Fold the paper in half between Saturn and Sun and on the fold mark/draw Jupiter. Fold the paper in half between Jupiter and Sun, and on the fold put a number of dots and write Ceres/Asteroid Belt. Fold the paper in half between Ceres and Sun and on the fold make a mark and label Mars. This is where Bode's descriptor stops. But between Mars and Sun make 3 equally spaced dots and mark them Earth Venus and Mercury.

You have to try the cash register thing to truly appreciate the simplicity of it.

Pete