T
his chapter chronicles the formation of Earth and the creation of life.
Earth was born during a time of unusual stellar formation. Only a small
percentage of the stars in the Milky Way galaxy are single, medium-sized
stars such as the Sun, and fewer yet have a system of orbiting planets.Therefore,
the Sun with its nine planets and their satellites is considered a rarity among stars.
Earth is unique among the planets, with its roving continents and evolv-
ing life-forms.It is the only planet with a water ocean and an oxygen atmos-
phere. It also has a rather large moon compared with its mother planet, a
pairing that still defies explanation.The atmosphere and ocean evolved during
a tumultuous period of crustal formation, volcanic outgassing, and cometary
degassing. Numerous giant meteorites slammed into Earth, adding unique
ingredients to the boiling cauldron. Raging storms brought deluge after del-
uge and unimaginable electrical displays. Out of this chaos came life.
THE SOLAR SYSTEM
Far back in the very obscured past, some 12 billion years ago, the universe
originated with such a force that the farthest galaxies are hurling away from
PLANET EARTH
ORIGIN OF LAND AND LIFE