    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
       Quaternary
  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
  I
  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
  O
  I    Triassic                     -          240 million     First dinosaurs, Abundant cycads and conifers
  C
                                                               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.
  P
                              Mississippian    360 million     Large and numerous scale trees and seed
  A
                                                               ferm.
  L
       Devonian                     -          410 million     First amphibians; ammonites; fishes abundant
  E
       Silurian                     -          435 million     First terrestrial plants and animals
  O
  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)
                                                           663