Many people have sacrificed their lives to quench the thirst for knowledge and to satisfy his curiosity to gain knowledge.
In the olden days people used to worship sun and moon thinking them sacred heavenly bodies. But the scientific investigation had proved that sun is an ordinary star and moon is a planet like other planets. After this the man has entered the age of the space travel.
The invention of rocket was the first step in space travel. Scientists had already discovered that there was neither air nor water on the moon. The moon was the first target of the man. The moon is our nearest neighbour.
It is about 300000 kms from the earth. A space ship travelling at a speed of 4000 kms. per hour can cover this distance in 10 hours.
The scientists had further discovered that the surface of moon is rough and full of craters, rocks and mountains.
America was the first country in the world whose astronauts landed first on the moon. Scientists now are trying to find out if there is life on Mars or not and they are planning to conquer it also.
Many centuries after that space travel can be taken as an excursion tour by the rich people of the world who can afford a huge amount for their will.