Area 51 Highway
The highway along Area 51 is usually quite deserted, so this picture is quite the rarity. Here we see a government car transporting an object, though it is quite unclear what it is. Many believe it could be a UFO underneath the tarp.
The Graf Zeppelin
In 1928, a German commercial plane called the Graf Zeppelin flew directly over Washington DC. Such as aircraft had not ever been seen in the United States before, causing many people to become frightened.