system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why would the U.S. Armed Forces test a missile like the one seen last night so close to a heavy populated city? I understand it was not armed, but they had to know it would be mistaken for a UFO or other threat.

Also, to any ballistic experts or veterans, what kind of missile was that? It's large blue appearance is just odd to me.
gpt
It was a Trident II missile.

The large blue appearance has nothing to do with the type of missile. Rather, it has to do with the time of launch (shortly after sunset, IIRC). High up, the sun was still above the horizon, and lit up the exhaust gasses.