Related Clues:

• They're from waaaay out of town
• They're certainly not from around here
• Some warriors in 'War of the Worlds'
• Org. that administers PSATs and GREs
• Ones who are worlds apart
• Little green men?
• 19-Across passengers
• Pilots who did not attend flight school
• They're not from around here
• Landon and an alien from Melmac
• Short tabloid subjects
• Brief strangers?
• Non-earthlings, for short
• They travel a long way to get here
• Some aliens, familiarly