It is named after the German astronomer Johann Gottfried Galle.

[1] Galle is often known as the "happy face crater" because pareidolia causes a curved mountain range in the southern part of the crater and two smaller mountain clusters further north to appear to be a smiley face.

A second "happy face crater", smaller than Galle and located at 45.1°S, 55.0°W in Nereidum Montes, was discovered by the Mars Reconnaissance Orbiter on January 28, 2008.

[2] As the smiley is a key motif in the comic book Watchmen by Alan Moore and Dave Gibbons, the crater was used as a story location after the coincidence was noted by Gibbons.

"[3] The crater also appears in the same scene during the film adaptation.