Over a period of time, there were many evidences that supported the idea of aliens’ existence. Though, most of the evidences such as photographs, reports and human’s experiences are remained as a mystery. Nevertheless, I strongly believe the fact that aliens exist. First of all, advanced science technology has been proving the lives of aliens.The scientist called ‘Frank Drake’; he created an equation to calculate the number of creatures those habits outside of the earth. Therefore, as a result of the equation, he asserted that there might be 100,000 to 1000,000 lives living in the whole universe. From then, more and more scientists and people assumed about the existence of the aliens. Also, numerous scientists have approved by presenting their theory. For example, Stephen Hawking who is one of the famous physics scientist, recently he have made an assertion that aliens DO exist. Moreover, NASA had found a few extrateresterial bacterias which shows the bases of their existence. However, I believe that there would be more clues for those aliens because previously, people who had worked in NASA are starting to make their statement that NASA is trying to hide some portion of the information they have found out. Following this, I am sure about that soon there would be more assertion would be made to support this idea.