This image is from the Library of Congress site noted below. Read more about Carl Sagan's 1954 Reading List found in his papers at:
Sterling College is a small, liberal arts college in central Kansas. This postcard was one of two I bought at the same time, both addressed to Ed Bakis, and postmarked in 1958.
I didn't recognize the language, but put some of it into an online translator, which told me it was Estonian.