The Day Mars Invaded Earth
The film's storyline is a cross between George Pal's "The War of the Worlds" ( 1953 ) , and Don Siegel's "Invasion of the Body Snatchers" ( 1956 ) . 
<triplet> The War of the Worlds <subj> George Pal <obj> producer <triplet> Invasion of the Body Snatchers <subj> Don Siegel <obj> director