Vintage 1940s mid-century pulp science fiction magazine, "Astounding Science Fiction" from April, 1948. The cover story for this magazine is "Man on Mira" by R. S. Richardson. There are also stories by Lewis Padgett, A. Bertram Chandler and others. 

This is in nice vintage condition. We don't know anything about grading pulp magazines, but this issue does have light wear and age. There is a "4 8" in ink on the bottom edge of the pages.