Sector 5
From Tardis Wiki, the free Doctor Who reference
This topic might have a better name.
There is also a sector 5 on Earth (Spearhead from Space)
Talk about it here.
Sector 5 was a region of Zeta Minor. There, Professor Sorenson made what he believed to be the "vital discovery" in his attempt to find an alternate power source for the Morestrans — a rich vein of anti-matter minerals with a purity greater than seventy percent. (TV: Planet of Evil)