One fine day, an apple falls on a persons head and BANG! There goes the theory of gravity and the person who put forwarded it was SIR ISSAC NEWTON. He envisioned the law of gravity between the planets in the 17th century though first journey to the moon was only in the 20th century. What is this interesting factor so called gravity? By definition gravity is the force of attraction which one body attracts the other and it is present all over the universe. Gravity is everywhere! The ground pulls us and this is why we are able to walk. Even other planetary objects exert the gravitational pull on us, but this doesn’t happen. Why? This is because the earth itself is a massive body which exerts equal gravitational force on the other celestial objects. This is how all the planets are placed in the space. This gravitational force makes the planets to maintain the orbit and even the satellites are placed in the space and are made to revolve around the earth. Our planet, the earth has a gravitational constant of g=9.8 m/s2. This is the force which makes us do the everyday life. The gravitational constant of the moon is 16.7 m/s2 and this is the reason why astronauts jump on the moon instead of walking. Even the astronauts feel “the zero-gravity” in spaceships. This is because the spaceships are already falling towards the earth and this makes them feel weight less and they feel the zero-gravity effect. Gravity is incredible abstract noun which does great thing and makes us live!