Planetary Evolution

Spiral galaxies are an excellent example of the evolving nature of a collapsing gas cloud. Due to their size the process occurs in slow motion compared with the evolution of a solar system. A non-rotating spherical gas cloud would collapse under gravity uniformly. A rotating gas cloud, due to centrifugal forces, will collapse to a disc. An eccentric or slightly non-spherical rotating gas cloud, due to the non-linear gravitational forces, would collapse to a spiral. There is no need to prove this, the evidence is present in every galaxy.

Spirals form with the radii of the spiral increasing by 1.618 for every 90 degree revolution around the central point. This is evident in galaxies and the patterns of snail shells. If these locations are points at which planets can form, the orbits of the moons of Jupiter and the planets of our solar system would fit this pattern. The four large moons of Jupiter fit exactly. The planets do so if it is assumed the asteroids form 2 adjacent rings. The predicted orbits in AU (measured data in brackets) are Mercury 0.38 (0.39), Venus 0.61 (0.7), Earth 1.0 (1.0), Mars 1.6 (1.5), Asteroids 2.6 and 4.2 (2.6 to 4), Jupiter 6.8 (5.2), Saturn 11 (9.5), Uranus 18 (19.2) Neptune 29 (30).

The mass of gas giants, with the exception of Uranus, decreases with distance from the sun. Uranus has clearly undergone a catastrophic event by the nature of it’s near 90 degree inclined axial rotation. This may have resulted in significant mass loss. Most of the Earth’s mass is iron. If it is assumed 65% of the Earth is iron, as the mass abundance of iron in the solar system is around 0.12%, the original mass of the spiral ring that formed the Earth, including hydrogen and helium would have been around (1/0.0012)/0.65 = 1300 times the Earth’s mass. This again shows an increase in mass available in spiral arms closer to the sun.

Near to a star planets might not retain hydrogen and helium long and so their mass is lower and their elementary composition different. If it is assumed that mass available reduces linearly with orbital distance and that within 4 AU hydrogen and helium are not retained, the Earth masses predicted are (measured data in brackets), Venus 1.58 (0.82), Earth 0.98 (1), Mars 0.6 (0.1), Jupiter 190 (318), Saturn 117 (90), Uranus 73 (15), Neptune 45 (17). Mercury will have lost significant amounts of iron due to its near sun orbit.

Clearly in real spirals things aren’t this simple, as is observed in galactic spirals. Interactions between spirals and collisions would change the resultant planetary landscape. For example Venus’ slow axial rotation indicates a high impact collision at some stage in its history.

Data now being gathered on extra solar planets shows the presence of high mass sub 0.1 AU orbit planets. With this model even without hydrogen and helium, the mass of carbon, oxygen and iron is sufficient to explain these “hot-Jupiters“. For example in our solar system the mass available at an orbital distance of around 0.09 AU would be around 300 Earth masses. Provided the planet formed quickly enough or the star is still young and the carbon and oxygen are still retained, such high mass planets would exist.

The orbital distances of multi planet extra-solar planetary systems in many cases follow the 1.618 increase pattern.

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