Here I am addressing an issue somebody (-cough-mother-cough-) raised: shouldn't there be two "Ls" in "Tranquillity"?

Panel 1: Chief Maintenance Officer Houston Texas and an Assistant are standing next to a sign saying "Tranquility Base".

Chief's Assistant:

There. The new sign is completed.

Chief Houston Texas:

Very nice. One thing…

Panel 2: Close-up of the sign showing the word "Tranquility"

Chief Houston Texas:

… aren't there two "Ls" in "Tranquillity"?

Panel 3: Close-up of the Assistant

Chief's Assistant:

According to the O.E.D. both spellings are acceptable, this is just a pre-17th Century variant still commonly used in the U.S.

Panel 4:

Chief Houston Texas:

I see. Did you check that before or after you made the sign?

Assistant (indignant):

Before!!!

Chief Houston Texas:

Uh huh… really…

Chief's Assistant (quietly):

Besides, the proper spelling wouldn't fit on the sign properly.