Stability of Solar System

How stable is our solar system?
Where all the planets ,we have today,around
4.5 billion years ago?
I attended a public lecture awhile back in which the speaker(sorry can't
recall his name) told us
computer simulations of our solar system indicate
that Mercury will be ejected from our system sometime in the distant future.
This got me thinking about the distant past .
I wonder how many planet's we started out with?
Any thought's
Randy

Randy Ellig wrote:
How stable is our solar system?
Where all the planets ,we have today,around
4.5 billion years ago?
I attended a public lecture awhile back in which the speaker(sorry can't
recall his name) told us
computer simulations of our solar system indicate
that Mercury will be ejected from our system sometime in the distant future.
This got me thinking about the distant past .
I wonder how many planet's we started out with?
Any thought's
Randy




The further back in time... the greater number of bodies.
Have you a quantitative definition for planets?

Must weigh more than a breadbox and last longer than RichA's attention
span.
Olga



Sam Wormley wrote:

Randy Ellig wrote:
How stable is our solar system?
Where all the planets ,we have today,around
4.5 billion years ago?
I attended a public lecture awhile back in which the speaker(sorry can't
recall his name) told us
computer simulations of our solar system indicate
that Mercury will be ejected from our system sometime in the distant future.
This got me thinking about the distant past .
I wonder how many planet's we started out with?
Any thought's
Randy




The further back in time... the greater number of bodies.
Have you a quantitative definition for planets?

Randy Ellig wrote:
How stable is our solar system?
Where all the planets ,we have today,around
4.5 billion years ago?
I attended a public lecture awhile back in which the speaker(sorry can't
recall his name) told us
computer simulations of our solar system indicate
that Mercury will be ejected from our system sometime in the distant future.
This got me thinking about the distant past .
I wonder how many planet's we started out with?
Any thought's
Randy

From what I have read, the planet Mercury will be enveloped by the
swelling red giant sun in about 1.6 billion years. The same model
projects that Venus, Earth and Mars will be pushed away from the sun to
approximate distances of 1, 2 and 3 AU respectively by a combination of
increased solar winds and eventually the puffing off of the sun's
"atmosphere" to form a planetary nebula, much like the Ring or Dumbell
nebulae.
This all sounds very disturbing, but for some reason, I'm not worried
about it in the least.

We "started out" with no planets. There was a protoplanetary disc
circling the sun early on. From this disk, some theories suggest,
planets accreted by gravity. As their mass increased, the began sending
smaller bodies whizzing all over the place. This created the earth's
moon, by collision, then ruined it's showroom shine by bombardment.

Gravity pretty much cleaned out the space between the planet's orbits
over time. Outside the planet's orbits (which is to say, beyond
Neptune's orbit), the Kuiper Belt remained, unaccreted debris from the
early solar system. There, smaller objects sometimes collided, forming
KBOs (Kuiper Belt Objects), of which, according to some, Pluto and it's
moon Charon, and Quorar are two excellent examples.

Even further out, and stretching to a distance of 3 light years or so,
the Oort Cloud forms a spherical envelope of objects surrounding the
solar system. Passing stars and tidal forces send some of these objects
into the inner solar system, and we observe their passage as comets.

Some KBOs are also seen as comets, but they can be distinguished by
their relatively short periods and orbit directions. Generally they
orbit the sun in the same direction as the planets. Not necessarily so
with Oort Cloud objects.


Science has yet to locate the planet Krypton, or explain how an infant
from that world survived a journey in a chemical rocket that crashed on
earth and grew up to become Superman. Funding for this kind of research
is difficult to secure.


Clear Skies,
Uncle Bob

On Thu, 26 May 2005 00:08:55 -0400, "Randy Ellig"
wrote:

How stable is our solar system?
Where all the planets ,we have today,around
4.5 billion years ago?
I attended a public lecture awhile back in which the speaker(sorry can't
recall his name) told us
computer simulations of our solar system indicate
that Mercury will be ejected from our system sometime in the distant future.

OH my God! When? I need to get photographs! :-)

This got me thinking about the distant past .
I wonder how many planet's we started out with?

There's no real way of knowing, but I'd suggest that the way we look
now is pretty much it, that is, it would have only been smaller
objects than Pluto that we lost.


Any thought's
Randy



--

Find out about Australia's most dangerous Doomsday Cult:
http://users.bigpond.net.au/wanglese/pebble.htm

Astronomy pages:
http://users.bigpond.net.au/wanglese...Astronomy.html

"You can't fool me, it's turtles all the way down."

One of the things that you have to remember about computer simulations is
that they are DIGITAL representations of what is happening. This means that
the numbers put into the simulation are only approximations of reality.
Sadly, slide rules are no longer used but if they were, people would be a
lot more aware of the problems of approximations. With slide rules, the
error band of what is the right answer becomes significant a lot faster than
using a calculator.

--
Why isn't there an Ozone Hole at the NORTH Pole?

On Thu, 26 May 2005 00:08:55 -0400, "Randy Ellig"
wrote:

How stable is our solar system?
Where all the planets ,we have today,around
4.5 billion years ago?
I attended a public lecture awhile back in which the speaker(sorry can't
recall his name) told us
computer simulations of our solar system indicate
that Mercury will be ejected from our system sometime in the distant future.
This got me thinking about the distant past .
I wonder how many planet's we started out with?
Any thought's

Strictly speaking, no body in the Solar System is in a stable orbit. The
dynamics of the Solar System reflect metastability, and are chaotic.
That said, the region of metastability is broad, and I don't believe
that any calculation is possible that could predict the ejection of
Mercury beyond a probabilistic solution. The situation is further
complicated by the unpredictable interaction of planets with large
objects occasionally entering the inner Solar System, either from
interstellar space or from the Oort cloud. In the absence of such
events, however, I have read that there is a high probability of the
current planets still being here, and in similar orbits, when the Sun
stops burning (the inner planets may be orbiting inside the enlarged Sun
at some point, however).

_________________________________________________

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com

On Thu, 26 May 2005 04:38:43 GMT, Sam Wormley
wrote:

Randy Ellig wrote:
How stable is our solar system?
Where all the planets ,we have today,around
4.5 billion years ago?
I attended a public lecture awhile back in which the speaker(sorry can't
recall his name) told us
computer simulations of our solar system indicate
that Mercury will be ejected from our system sometime in the distant future.
This got me thinking about the distant past .
I wonder how many planet's we started out with?
Any thought's
Randy




The further back in time... the greater number of bodies.
Have you a quantitative definition for planets?



Anything larger and rounder than Pluto
that doesn't orbit another planet.
-Rich

There are no computer models accurate enough to predict planetary
motions/positions beyond a few hundred thousand years on either side of
"right now". What happens in the distant future, or what transpired in
the distant past is anybody's guess.

Randy Ellig wrote:
How stable is our solar system?
Where all the planets ,we have today,around
4.5 billion years ago?
I attended a public lecture awhile back in which the speaker(sorry can't
recall his name) told us
computer simulations of our solar system indicate
that Mercury will be ejected from our system sometime in the distant future.
This got me thinking about the distant past .
I wonder how many planet's we started out with?
Any thought's
Randy

But if they are box-turtles then the stacking is stable. If they are
snappers then the state is metastable. I wonder which it is