Scalos was a class M planet located in an outer quadrant of the galaxy, homeworld of the humanoid Scalosians.
The population was destroyed by radiation poisoning. The planet had a population of 900,000, and had a rating of 7 on the industrial scale before 2267. When it was visited by the Starfleet vessel USS Enterprise, only five hyperaccelerated individuals remained. (TOS: "Wink of an Eye")
For the 2006 remastered version of "Wink of an Eye", the generic planet representing Scalos (also seen as Argelius II) was replaced with a unique, computer-generated version. The cityscape on the surface of the planet was also replaced with a new, high definition matte painting - the original had been a reuse of the Eminiar VII city from "A Taste of Armageddon".