Planet Earth is one of the many plants of this universal system which is inhibited by intelligent species called as HUMANs. To explore the earth system we get visitors from across the universe and the milky way whom we call ALIENS. ALIEN is a word tagged to something which did not originate on this earth, sometimes also referred as extraterrestrial life being. The hypothetical form varies from a small bacterial like organism to some super complex human being. The testing and research on this hypothesis is clubbed under the branch of exobiology OR astrobiology(study of the earth viewed in its astronomical context). Scientists consider the extra terrestrial life to be plausible and hence there is an ongoing research happening since the early 20th century with use of radio frequencies and telescopes and higher gadgets. In 2013 astronomers reported based on kepler space mission data that there could be around 40 billion earth size planets orbiting their zone