The Earth in the Solar System

• Introduction

  • Night sky view: Stars, planets, and moon
  • Celestial bodies: Objects shining in the night sky
  • Constellations: Recognizable patterns formed by groups of stars
    • Example: Ursa Major or Big Bear
    • Saptarishi: Group of seven stars
    • Pole Star: Indicates the North direction

• The Sun

  • Center of the Solar System
  • Huge and made of extremely hot gases
  • Provides gravitational pull binding the solar system
  • Ultimate source of heat and light for the solar system

• The Planets

  • Eight planets in order of distance from the Sun:
    • Mercury
    • Venus
    • Earth
    • Mars
    • Jupiter
    • Saturn
    • Uranus
    • Neptune
  • Two types of orbits:
    • Orbit: Fixed elongated path
    • Revolutions: Movement around the Sun
    • Rotation: Movement on the axis

• The Earth

  • Third nearest planet to the Sun
  • Fifth largest planet
  • Shape: Geoid (flattened at the poles)
  • Blue Planet: Two-thirds surface covered by water
  • Supports life due to favorable conditions

• The Moon

  • Earth's only natural satellite
  • Diameter is one-quarter of Earth's
  • Moves around Earth in about 27 days
  • No water or air; surfaces have mountains and craters
  • Phases of the Moon: Changing shapes visible from Earth

• Other Celestial Bodies

  • Asteroids: Tiny rocky bodies revolving around the Sun (found between Mars and Jupiter)
  • Meteoroids: Small pieces of rocks moving around the Sun
  • Galaxy: Huge system of billions of stars
    • Milky Way Galaxy: Our galaxy, also called Akash Ganga
  • Universe: Millions of galaxies making up the universe