There are so many people in the world now.There will be a lot more next century.The earth will be very crowded and there will be little room for each person..Probably there will be only space for standing 600 years later.That will be a very serious problem.
So man is thanking of a way to solve the problem.
The moon is the earth.Maybe man will go to live on the moon one day. But there is no air plants, no life there. So scientists are doing experiments in many ways.They have to solve many problems before man can live on the moon. I am sure our dream will come true in next century.