My original tumblr post was here. This image was researched by Bacchus at ErosBlog as part of the “Δ commission.” The research was originally published at Hedonix as “Δ 059 – The Brain In The Sphere.” Here is what Bacchus found.

This image is a cropped and crudely-photoshopped version of the cover of Marvel Science Stories from August 1938.

According to this page, the cover artist is Norman Saunders, a prolific pulp artist from the 1930s through the 1960s. A great deal of additional information about Norman Saunders is available at NormanSaunders.com. Interestingly, this is the artist who painted the famous Mars Attacks trading cards in 1962.