Unusual or unexpected things that happen
Strange events
Destroyed in the air by a missile or weapon
Shot down
Balloons that are unknown and hard to explain
Mysterious balloons
The height of something above the ground
Altitude
A strong desire to know or learn something
Curiosity
Someone who speaks for a group or organization
Spokesperson
Vehicles that fly
Crafts
Stress or pressure between people or countries
Tension
Secretly watching to get information
Spying
Clear facts or evidence that show something is true
Proof
Found and brought back something that was lost
Recovered
Watching or following the movement of something
Tracking
