Solar System Dynamics : The Solar Year was once shorter than it is now ...

In the earliest era of the formation of the Solar System the not yet condensed primordial gas and dust rotated around the forming Sun at a much higher rotational rate. The uncondensed material rotational rate was at least 110% to 146% faster than in the current era.

The gravitational interactions (gravitational well collisions) of the larger bodies that were created from the primordial gas and dust slowed the rotation rate of all bodies in the Inner Solar System (and the Earth Moon Couple) measurably in the past ~4.5 Billion years. 

The Sun's influence in the orbital slowdown has been nominal. The Sun has only made orbits of all bodies in the Solar System more circular over the past 4.5 Billion years. The Sun's "gravitational well" has uniformly perturbed all bodies (overall not slowing down or speeding up any of them) over the past 4.5 Billion years.

The Sun is the gravitational stabilizing body of the entire Solar System, as far as the orbital dynamics of the condensed bodies we know today.

In the early era of the solar system, when the outer Gas Giants (and Ice Giants) were closer to the Sun (and in a different sort order to each other) the Solar Year at {1.0 Earth Sun Radii, ~8 light seconds} was shorter. The multiple gravitational well interactions that were needed to slow down the bodies in the Inner Solar System would take between 4.5 Billion to 600 million years to produce a result close to the current orbital parameters.

At least one Gas Giant was expelled from the Solar System as a by product of the condensed body interactions. This Gas Giant's residual gravitational influence on Asteroids in the Solar System was the only factor that made possible its detection.

The Solar Year was shorter because the multiple and ongoing gravitational interactions between the bodies had not frictionally slowed down all of the bodies circular rotation around the Sun.

It is probable that the rotation rate of the primordial gas and dust in the Solar System around 5 Billion Years ago at {1.0 Earth Radii} was at least 250 {Days per Solar Year} at maximum and that the rate of 330 {Days per Solar Year} at minimum at {1.0 Earth Sun Radii, ~8 light seconds}.

Most of the orbital slowdown of the condensed bodies (of the Sun) occurred from the Early Hadian to the Late Bombardment Era on the Earth's geological scale. The orbits of the bodies would not be fully stable until after the Cryogrean Era. The fine tuning, and orbital resonances (that exist today) for the affected Solar System bodies did not fully stabilize (to within "near current" orbital parameters) until the Devonian Era.

The Orbital Mechanics and Dynamics

Uncondensed gas and dust, as it forms a uniform sheet (that leads to the formation of a solar system) speeds up its circular rotation rate around the sector where a star is about to form.

However, this quasi-uniform gas and dust sheet would initially have few large bodies (larger than Moon radius) with large enough gravitational wells that would act to slow down (or occasionally speed up) the orbit of any particular body.

As planetary bodies form of the Rock and Gas Giant type, there are more complex interactions of the gravity wells of these bodies. Even tiny Asteroids have orbiting moons. Local gravity well interaction is everywhere with small bodies.

Gravity's influence with respect to bodies of Jovian size or smaller is more local, not infinite. The gravitational influence of the Sun extends out measurably to about {1 Light Year}, but is very weak beyond the Pluto-Charon Couple.

As the bodies condensed to form the Sun [and all of the Inner Planets (Mercury, Venus) and Outer Planets (Mars, Jupiter, Saturn, Neptune)] the gravitational interactions of the not yet resonant solar system bodies was more profound and more pronounced then in the current era. The more abrupt and more common gravitational well interaction significantly slowed down the bodies in the Inner Solar System.

243 Ida, an all to stereotypical example of a small Asteroid with something in its orbit

243 Ida has a moon...

Gravitational collisions, as in the Minvitch 3 Body Collision Problem

Due to the frictional interaction of gravitational attraction each time a body passes within meaningful gravitationl influence of another body -- both bodies may be either sped up or slowed down due to the collision of the gravitational wells in Einstein's Spacetime. The long term tendency is for the bodies to slow down each other's circular rotation rate around the sun.

Jupiter, Mars and Venus's known gravitational influence




Geological eras

Mechanics & Dynamics of Gravitational Bodies

Bodies still causing frictional slowdown

Bodies that used to cause frictional slowdown, but do not do so now except when at nearest approach
Bodies that likely never created any frictional slowdown, at least for Earth and Mars

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Max Power

09 September 2013

09 September 2013

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