Thanks to movies and TV shows, most people have the image of little green men or skinny bug-eyed gray figures in their heads when they think of aliens.
But perhaps Hollywood got it wrong...at least according to some new findings.
Scientists writing in the International Journal of Astrobiology argue that extraterrestrial life could actually be purple.
The theory has been around since 2007 and says that simple bacteria and single-celled organisms can create energy from retinal pigments, rather than chlorophyll like many plants do.
These organisms, which have been found in oceans and the Antarctic Dry Valley on this planet, are some of the earliest life discovered on Earth and are tinted purple.