The Universe: Big Bang! , expanding universe, red shift, doppler effect; residual heat

Solar System: observations, flat plane of the ecliptic, rotation, differentiation of terrestrial and Jovian planets; development, solar nebula, planetesimals, continued accretion,

Earth: initial accretion, melting, gravitational contraction, impact and continued accretion, short half-life radioactive decay; differentiation, iron is heavy, iron has low melting temperature, core, mantle, crust

Explain the Big Bang! theory for the origin of the Universe, and explain the two main lines of evidence that support this theory.

How did the solar system form? What observations about the solar system led to the development of this theory?