My original tumblr post was here. This image is an illustration by Virgil Finlay for a novel Things Pass By by Murray Leinster that appeared in the Winter 1955 edition of Fantastic Story Magazine. You can download the whole issue (CBZ file, about 95MB) here via the website Pulp Covers. The image bears the caption “The Things from deep space were moving toward the sun…and Dirk Braddock knew that they would destroy human civilization!” The image was originally posted by Not Pulp Covers.