Why is mercury named after Maiestas

A little history .

Actually, it's not. I'm sorry. Mercury is named after Hermes (Mercury in Roman form), the god of travelers, and the messenger of the gods. They named Mercury this because it moves fast. Just like Hermes.

I haven't heard of Maeistas... However I do know that the planet Mercury was named after a Roman god. The Greeks and Romans both worshiped a common god named Hermes (or Mercury depending on which culture) who was the messenger god ofcommerce, travel and thievery and had winged feet. He was the fastest of the gods and when Mercury was discovered it was noticed it had the fastest orbit! It completes one orbit in about 88 earth days.
Hence, the planet Mercury was named after the god because it moved so fast in the night sky.

Sorry, but Mercury was named after the Roman God Mercury. Mercury was the messenger of the Gods. An apt name for the planet that has the fastest transit of the Sun.
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"Maiestas" means "Majesty"

No direct relationship to Mercury....