The word alien comes from the Latin word ‘ali?nus’, which means “not one’s own, of others, foreign, strange”. It is derived from the Latin word alius, which means “other”. The concept of aliens has been around for a long time with each school of philosophy having different views on them. The very first speculations about a life existing beyond the Earth can be found in the discussions amongst Epicurean philosophers in ancient Greece and their Roman disciples.