THE SOLAR SYSTEM
TERMS
Located at the Milky Way galaxy, it has 100 billion stars, 100 light years across, it is from the Local Group, Virgo
Supercluster, currently 4.6 billion years old
Its mass is concentrated at the center (Sun) while
angular momentum is held by the outer planets.
Orbits of the planets are elliptical and on the same
plane.
All planets revolve around the Sun. Periods of revolution of the planets depend on their
distance from the Sun.
All planets are located at regular intervals from the Sun. The planets rotate prograde, except Venus and Uranus.
RIVAL THEORIES
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1. Nebular Hypothesis
2. Encounter Hypotheses
3. Protoplanet Hypotheses
PLANET FEATURES
Encounter Hypotheses
Buffon’s (1749) Sun-comet encounter that sent matterto form planet
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James Jeans’ (1917) Sun-star encounter that would have drawn from the Sun matter that would condense to planets
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T.C. Chamberlain and F.R. Moulton’s (1904)
planetesimal hypothesis involving a star much
bigger than the Sun passing by the Sun and drawsgaseous filaments from both which planetesimals were formed
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Ray Lyttleton’s (1940) Sun’s companion star
colliding with another to form a proto-planet that
breaks up to from Jupiter and Saturn
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Nobel Prize winner Harold Urey’s compositional
studies on meteorites (1950s) and other scientists’ work on these objects led to the conclusion that meteorite constituents have changed very little since the solar system’s early history and can give clues about their formation. The currently accepted theory on the origin of the solar system relies much on information from meteorites.
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Protoplanet Hypotheses
4.6 billion years ago—contraction of the Orion
arm of the Milky Way galaxy due to gravity
Most mass move to the center—forming Sun,
and the remaining materials form a disc that
formed planets and momentum is transferred
outwards
SCIENTIFIC THOUGHT
Nebular Hypothesis
Emanuel Swedenborg, Immanuel Kant, and
Pierre-Simon Laplace (1700s) Independently thought rotating gaseous cloud that cools and contracts in the middle to form the Sun and the rest into a disc that become planets Failed to account the distribution of angular momentum in the solar system
