For thousands of years, humanity has wrestled with the idea we may not be alone in our solar system.
Speculation that aliens might exist dates back to philosophers in ancient Greece, but it was the middle of the 20th century when people's imaginations really began to run riot — suddenly 'little green men' were everywhere in popular culture.
Although the use of the phrase is believed to have originated in 1908, it was between the 1920s and 50s that green Martian characters were plastered all over the covers of science fiction magazines and later people's TVs.
The reality is that if extraterrestrial life does exist in our solar system it will be of a more simpler variety, perhaps hidden in Venus' clouds, beneath Mars' surface or in the vast underground oceans of one of Saturn's icy moons.
But where else is the best bet of finding it? MailOnline speaks to a number of experts to find out.
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