NCERT Class 6 Geography Chapter 1: Earth in Solar System YouTube Lecture Handout

Doorsteptutor material for CBSE/Class-6 is prepared by world's top subject experts: get questions, notes, tests, video lectures and more- for all subjects of CBSE/Class-6.

Get video tutorial on: Examrace YouTube channel

NCERT Class 6 Geography Chapter 1: Earth in the Solar System

Galaxy

  • Gravitationally bound system of stars, stellar remnants, interstellar gas, dust, and dark matter
  • Example, Milky Way (contains Solar System)
  • March 2016, Most distant galaxy – GN-z11
  • Hubble՚s Classification
    • Elliptical (E)
    • Spiral (S) : Andromeda & Sombrero (unbarred)
    • Lenticular

Celestial Bodies (Sun, Moon, Objects in Night Sky)

Illustration: Celestial Bodies (Sun, Moon, Objects in Night Sky)
  • Celestial Bodies
  • Emit their own heat and Light – Star (Example, SUN)
  • Don՚t emit their own light – Planets
  • Planets – Greek Word – Planetai i.e.. Wanderer
  • NORTH STAR – POLE STAR – Indicates north Direction

Constellations (Group of Stars) – 88 Officially

Illustration: Constellations (Group of Stars) – 88 Officially
Illustration: Constellations (Group of Stars) – 88 Officially

Planets

Illustration: Planets

Dwarf Planets

  • Ceres - largest object in asteroid between Mars and Jupiter
  • Pluto – Small Size, Offbeat Orbit, Beyond Kuiper Belt, Now Planetoid
  • Eris - 2003 UB313 – 10th planet & largest dwarf discovered
  • Oort Cloud are composed of ices like ammonia, methane & water
  • Kuiper Belt – Ice belt beyond Neptune
  • Planet Nine in Kuiper Belt is 10 times the mass of Earth and 5,000 times the mass of Pluto.
  • Kuiper similar to asteroid belt between Mars and Jupiter

Earth

Illustration: Earth
  • Shape – Geoid or Oblate Spheroid
  • 3rd nearest to sun
  • 5th largest planet
  • Age: 4.54 billion years old
  • Chemical composition of Crust – Silica, alumina, lime
  • Earth՚s mass - Iron (32%) , Oxygen (30%) , Silicon (15%)
  • Earth՚s Crust – 47% Oxygen
  • Rotation & Revolution
  • Earth՚s perihelion (closest) around 3 January & aphelion around 4 July.

Moon

  • Natural Satellite – Celestial body that moves around planet
  • Moon՚s Diameter – 1⟋4th of earth 5th largest natural satellite
  • Tides: Gravitational attraction between moon and earth
  • Ganymede – Largest moon in Solar System (Jupiter)
  • Titan – 2nd largest moon in solar system (Saturn)
  • Distance from earth: 384,400 km
  • Sidereal Month: w. r. t. to distant stars, 1 revolution relative to stars – 27.32 days
  • Synodic Month: w. r. t. to Sun, time taken by moon to reach the same visual phase - 29.53 days. Longer period is required to achieve similar alignment of Earth, the Sun, and the Moon.
  • Chandrayaan-I and II, TeamIndus (Unmanned spacecraft to moon)
  • Asteroids
  • Meteoroids
  • Comets
  • Pulsars

Manishika