And that is why so many believe it's a missile.
It's known as an optical illusion.
A high altitude plane, coming from beyond the horizon will appear to be going more or less vertical.
The Sun, or Moon, when rising over the ocean horizon,do the same thing.
TAKE A LOOK at the picture you posted, and first tell yourself the object is going away from you. Then look at it and tell yourself the object is coming towards you.