On sale date from the publication date found at the Catalog of Copyright Entries, Part 2, Periodicals, New Series, Volume 35, January-December 1940, Numbers 1-4. Second class permit. Copyright number 440220.
Splash panel alleges New York City is destroyed... but no evidence of this in the story. Letterer credit added by Craig Delich 2010-3-13.
The first line of text reads: "Space" and Dianna are on their way to Mars for the purpose of destroying the great Martian central brain..........."
Letterer credit added by Craig Delich 2010-3-13.