Ufos at the sky --- Image by © Sagel & Kranefeld/Corbis
Invasion --- Image by © 68/Colin Anderson/Ocean/Corbis
23 Aug 2002 --- Green Alien Face --- Image by © Envision/Corbis
Extraterrestrial in the Mist --- Image by © Mike Agliolo/Corbis
Extraterrestrial --- Image by © Mike Agliolo/Corbis
Boy Wearing Alien Mask --- Image by © Rainer Holz/Corbis
Pacific Islander woman wearing futuristic combat gear --- Image by © Colin Anderson/Blend Images/Corbis
06 Dec 2009 --- A thin veil of gaseous material surrounding the blue-white star Vega is seen here as a hazy sunrise on a small moonlet in orbit around the cloudy planet. Vega itself is still below the horizon. --- Image by © Stocktrek Images/Corbis
August 24, 2010 --- Alien, computer artwork. --- Image by © VICTOR HABBICK VISIONS/Science Photo Library/Corbis
A man out in the foggy wilderness is being abducted by a U.F.O. with a bright beam of light. --- Image by © C.J. Burton/Corbis
20th century --- Magazine Cover with Robot War Machines by Blade Gallentine --- Image by © Forrest J. Ackerman Collection/CORBIS
1985 --- Montage of Science Fiction Scenes with Portrait of Illustrator Frank R. Paul by Anton Brzezinski --- Image by © Forrest J. Ackerman Collection/CORBIS
1985 --- Painting of Science Fiction City Battle by Anton Brzezinski --- Image by © Forrest J. Ackerman Collection/CORBIS
Ufos above the city --- Image by © Claudius/Corbis
Alien --- Image by © Gregor Schuster/Corbis
Man in Alien Costume --- Image by © Rainer Holz/Corbis
Space Alien --- Image by © Mike Agliolo/Corbis
Nevada, USA --- Aluminum alien statue near Extra Terrestrial Highway in Nevada --- Image by © Momatiuk - Eastcott/Corbis
Alien making contact --- Image by © Colin Anderson/Blend Images/Corbis
Red robot attacking with beams from eyes --- Image by © Ikon Images/Corbis
Inflatable alien with Welcome to Roswell sign in background --- Image by © Vstock LLC/Tetra Images/Corbis
Alien abduction. Alien beings examine a human woman on their spaceship. posed by models 1998 --- Image by © David Levenson/Corbis
15 Nov 2012 --- A pair of P-51 Mustang Fighter planes blowing up a crashed alien vehicle and it's robotic crew member, during Earth's ongoing secret war with this robotic enemy race. --- Image by © Mark Stevenson/Stocktrek Images/Corbis
20th century --- Painting of a Science Fiction Scene with Robots and Spacemen by Anton Brzezinski --- Image by © Forrest J. Ackerman Collection/CORBIS
Alien --- Image by © Randy Faris/CORBIS