Related Clues:

• Klingons, e.g.
• Roswell visitors?
• S.A.T. org.
• 'Star Wars' walk-ons
• 'The X-Files' extras, briefly
• 'The X-Files' extras
• S.A.T. administrator
• Venusians, e.g.
• UFO passengers
• They can cover a lot of space
• Space invaders
• Visitors to Earth, for short
• Aliens, for short
• Latin connections
• They cover a lot of space?