Including...
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Books make many statements as though they are facts, as opposed to theories
Much based on mathematical models which no normal mortal can hope to understand
The processes discussed happened a long time ago
These represent theories based on current levels of understanding
There are no direct methods to observe the formational process of the Solar System
All methods are essentially indirect and involve some major assumptions
So, let's keep the uncertainty factor in mind
Any theory has to accounts for several observations
Dynamic constraints
Planets all move around sun in the same direction
All are on the Plane of the Ecliptic
Approx. in plane of the sun's own rotation
Most planets have same sense of rotation, as do their moons
Chemical constraints
Two basic types of planets
Separated by transitional asteroid belt
Inner planets are "rocky" (Mercury to Mars)
Outer planets are "gaseous"
Basically giant farts in space
Jupiter & Saturn are essentially small stars
Age constraints
Everything seems to have formed 4.5 billion years ago
This one is based on very limited work!
It is thought that the solar system formed by the condensation of a "nebula"
A nebula is a widely dispersed cloud of interstellar gas and dust
Slowly rotating in space and very cold (-270°C)
Gravitational attraction caused this matter to condense
Condensation resulted in faster rotation and an increase in temperature
Conservation of angular momentum
Collapse into a rotating disc of matter
Big bulge in the center with distended "arms" of matter
Led to the formation of the sun and planets
Most matter accumulated into the center to form the sun
At some point the amount of matter was sufficient to set off the nuclear reactions which cause stars to give off energy, but not right away
Proto-star: warmer than space but not hot enough to begin fusion
Fission vs. Fusion
Critical Mass
Anyway, "over the course of geologic time" enough matter came together to start the reaction
At the same time, planets were forming in the outer edges of the disc
The terms "accumulation, planetesimal, accretion" are used here
But for now, the following is important
Jupiter also has a lot of matter: almost like a Proto-star
Does not have "Critical Mass" so no fusion reactions
The accumulation process is still going on
Earth intercepts 200,000,000 pieces of space debris daily!
Most are very small (dust), but there are still some large chunks out there
More on this later, too