A film depicting an alien invasion of earth -- most often, the aliens are not friendly. "Watch the skies!" became the familiar refrain of this subgenre of the science fiction film in which alien visitors, usually hostile in nature, invade and/or attack Earth. It's up to the nation's top scientists and the military to find the aliens' weak point, thus defeating them and rescuing mankind from enslavement or extermination. This cycle of films reached its zenith of popularity in the 1950s with such gems as Earth vs. The Flying Saucers, Invaders From Mars, War Of The Worlds, and It Came From Outer Space. In some instances, there were societal critiques lurking beneath these "B"-movie texts, with the pro-pacifism message of The Day The Earth Stood Still and the anti-McCarthyism of the original Invasion Of The Body Snatchers commenting on significant issues of the day without addressing them outright and thus avoiding the wrath of the censors. Later, films like Close Encounters Of The Third Kind, Starman, and E.T. presented a kinder, gentler alien who sought to study the ways of mankind as opposed to eliminating them. In the 1990s, the alien invasion movie resurfaced with the blockbuster extravaganzas of Independence Day, Mars Attacks!, and Men In Black paying homage to the classics of the 1950s, updating them with big budgets and the latest in special effects.