THE SUN
· The sun is at the centre of the solar system.
· Its size is thirteen laky times as that of he earth.
· It is the nearest star to the earth.
· It is an ultimate source of energy for life one earth.
· Its diameter is 14 lakshkms.
· It is composed of 71% Hydrogen, 26% Helium and 2.5% other elements.
· Hydrogen and Helium are the main gases present in the sun.
· Within the sun, hydrogen is converted to helium due to nuclear fusion releasing a tremendous amount of heat and light.
· It has a surface temperature of about 6000˚C.
· Shining surface of the sun is called ph atmosphere, it appears like a duiscm, radiates energy and acts as a source of energy.
· The outer layer of sun’s atmosphere made up of thin hot gases, is called corona, corona is visible only during a total eclipse of the sun (of with a special solar telescope called coronagraph).
· The planet travels with the sun through millions of stars in our galaxy at a speed of about 70,000 km per hour.
· The sun is about 150millionkms away from the earth.
· Light (at speed of 300,000 km per second) takes about 8.5 minutes to reach the Earth from the sun.
THE PLANETS
· These are opaque bodies which continuously revolve around and are lighted by the sun.
· There are eight planets in the solar system.
· A ninth planet has been recently discovered by NASA naked as Carla.
· The sequence of planets according to their distance from the sun is mercury, Venus, earth, mars, Jupiter, Saturn, Uranus, and Neptune.
· The sequence of planets according to their size (in descending order i.e. from big to small) is Jupiter, Saturn, Uranus, Neptune, earth, Venus, mars, mercury.
· Jupiter is the biggest and mercury is the smallest planets of our solar system.