The Universe, Solar System

Geography Study Material

The Universe and the Solar System

• The study of the universe is called “Cosmology”.


• The name of our galaxy is “ The Milky way”. It a spiral galaxy.


• Black hole : The black hole is a collapsed star. The stars which have contracted so much that they have developed super density 1016 grams per cubic centimeter; supernova corpses of more than 3 times the mass of the sun are transformed into black holes.


• John Wheeler, an American physicist, was the first to use the term black hole.


• A black hole creates an area of immense gravity around an inconceivable dense point.


• Cygnus X-1 is a recently identified black hole.

THE SOLAR SYSTEM

• The solar system includes the Sun, Eight planets, Asteroids, ,Meteors, Comets, Inter planetory dust, Plasma.


• Mercury, Venus, Earth, Mars are Terrestrial or Rocky planets.


• Jupiter, Saturn, Uranus, Neptune are Jovian or Gaseous planets.

Some Facts about Planets :

MERCURY :
• Smallest planet, Closest to the sun, Fastest planet.



VENUS :
• Closest to the earth.


• Also known as “The Morning Star” and “The Evening Star”.


• It is also the Brightest and the hottest planet.


• Rotates in Anticlockwise direction.



MARS :
• Known as “The Red Star”.



JUPITER :
• It is The Biggest Planet.



SATURN :
• Least dense planet.


• It has 17 satellites.


• “Titan”, the biggest satellite of Saturn is said to have an atmosphere.



URANUS :
• It is the third largest planet.


• It rotates in Anti-clockwise direction.



NEPTUNE :
• It is the farthest planet from the sun.


• It is a greenish planet.