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
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
O First birds, First mammals dinosaurs and
Z Jurassic - 205 million
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)