    Earth is the third planet from the sun at a distance.
    It is the densest planet in the solar system.
    It is the fifth largest of the eight planets in the Solar System.
    It is also the largest of the Solar System"s four terrestrial planets.
    Earth is also known as Blue Planet.
    Earth formed approximately 4.54 billion years ago, and life appeared on its surface within
     its first billion years.
                                  GEOGRAPHICAL HISTORY OF THE EARTH
          System &                             Beginning
Era                         Series & Epoch                                 Some Distinctive Feature
            Period                             Years ago
  C                        Holocence/Recent      10000         Modern Man
  E                           Pleistocene       2 million      Early Man; Nothern Glaciation
  N                             Pilocene        5 million      Large Carinvores
  O                             Milocene       24 million      First abundant gazing mammals
  Z                            Oligocene       38 million      Large running Mammals
  O    Tertiary
                                Eocene         55 million      Many modern tyoes of mammals
  C                            Paleocene       63 million      First placental mammals
 M                                                             First Flowering Plants; climax of dinosaurs and
  E    Cretaceous                   -          138 million     ammonties, followed by Creataceous-Tertiary
  S                                                            extinction.
  O                                                            First birds, First mammals dinosaurs and
  Z    Jurassic                     -          205 million
                                                               ammonites abundant
  I    Triassic                     -          240 million     First dinosaurs, Abundant cycads and conifers
                                                               Extinction of most kinds of marine aminals,
       Permian                      -          290 million
                                                               including trilobites. Southern glaciation.
       Carboniferous         Pennsylvanian     330 million     Great coal forest, conifers. First reptiles.
                                                               Shark and amphibians abundant.
                              Mississippian    360 million     Large and numerous scale trees and seed
       Devonian                     -          410 million     First amphibians; ammonites; fishes abundant
       Silurian                     -          435 million     First terrestrial plants and animals
  Z    Ordovician                   -          500 million     First fishes; invertibrates dominant
  I                                                            First abundant record of marine life;
       Cambrian                     -          570 million
  C                                                            trilobites dominant
                                                               Fossils extremely rare, consisting of primitive
                                                               aquatic plants, Evidence of flaciation.
       Pre-cambrian                 -          4.5 billion
                                                               Oldest dated algae, over 2600 million years;
                                                               Oldest dated meteorite 4500 million years
                                     IMPORTANT FACTS ABOUT EARTH
Shape                                              Oblate ellipsoid or Geoid
Age                                                4.54 billion years
Mass                                               5.97 × 1024 kg
                                                   3.0 × 10−6 Suns
Volume                                             1.083 × 1012 km3
Radius                                             6,371 km
Surface area                                       510,072,000 km2
Land area (29.2 %)                                 148,940,000 km2
Water area (70.8 %)                                361,132,000 km2
Circumference                                      40,075.017 km (equatorial), 40,007.86 km (meridional)
Mean density                                       5.515 g/cm3
Rotation period                                    1 day (23h 56m 4.100s)
(length of day in Earth days)