One of the most common unanswered questions scientists find themselves asking is "Is there life on other planets?" Since the first famously documented UFO sighting in 1947, the idea of extra-terrestrial life has been debated almost non-stop. The subject has inspired many TV programs, such as The X-Files, and films (Mars Attacks, Independence Day, and the Men in Black films to name but a few). Scientists have come up with many new ideas and ways of trying to either prove or disprove the existence of life elsewhere.
Mars is a very similar planet to earth in relation to size and atmosphere. Therefore it seemed like the most likely place to search for life. At the end of the 19th century, an American named Percival Lowell built himself an observatory so that it was possible for him to study Mars in intimate detail when its orbit was closest to Earth. At this time it had recently been suggested that the planet had a system of channels on the surface, present from the evaporation of flowing water.
Looking through his telescope Lowell became convinced he could see a network of artificial canals. This led him to believe that there were intelligent beings on Mars who had built these canals. However, spacecraft have now visited Mars and found that there is no evidence of water at all. It is now thought that the lines he could see were the combination of Lowell's overactive imagination, and scratches on the lens of his telescope. We are now searching one of Jupiter's moons, Europa, as this seems to be the next likely place to hold life.
It is seen to be more likely, however, that we will find less intelligent life in one of two different ways: It may be possible for us to obtain material...