Venusians and Martians, in brief

• Classic video game villains
• Diminutive endings
• "Falling Skies" extras: Abbr
• Connections in old Rome
• Area 51 holdings, some speculate
• Visitors in sci-fi movies, often: Abbr
• Those who are not among us (or are they?)
• UFO people
• UFO pilots, ostensibly

Wikipedia Word definitions in Wikipedia
ETS is an abbreviation of: