If the human race were to inhabit another planet, how many people must we send to ensure that humans do reach that planet in enough numbers to live and propagate? Originally, the number was thought to be 150. However, now, scientists believe that the number would be much higher – 10,000 people! They also say that 40000 would be a better figure. One needs to factor in the idea that this space journey will require several generations of travel; issues that have plagued human generations such as war, and disease will have to be considered as well.