EXTRATERRESTRIAL LIFE is defined as life that does not originate from Earth. Referred to as alien life, or simply aliens, these hypothetical forms of life range fromsimple bacteria-like organisms to beings far more advanced than humans.The development and testing of theories aboutextraterrestrial life is known as exobiology.
Alien life, such as bacteria, has been theorized to exist in the Solar Sy...stem and quite possibly throughout the Universe.According to this argument, supported by scientists such as Carl Sagan and Stephen Hawking, it would be improbable for life not to exist somewhereother than Earth because our universe is somuch vast with so many galaxies and millions of solar systems and billions of planets !!!