Is this a plot hole: Urd?

[Senkusha]

So, I'm re-watching Ah! My Goddess again, and I'll admit it's been at least a decade since I first watched this anime, and I've only gotten through the first four episodes (before Urd's introduction), but something is sticking out in my mind.

Spoiler

I remember that Urd was banished from Heaven for a period of five terms. It's debated if this translates to 50 years, but regardless. Why is Belldandy the first goddess on Earth? Where is Urd at, if she's most likely on Earth during her banishment?

Obviously, I'll continue to watch the series, and perhaps my own questions shall be answered, but I never thought about this complication before.

 

[Senkusha]

Okay. Had I been just a little more patient, the answers would have revealed themselves automatically! Basically...

Spoiler

Because Urd came down to Earth to fix Keiichi's wish-- unauthorized at that, AND used her powers, again, unauthorized, became banished from Heaven.

I don't remember how closely the Ah! My Goddess TV series follows the manga. Ah! More Research...