Geological Chronicle
Fontenelle lies along the northern edge of Mare Frigoris in the northern part of the Moon. With a diameter of 37.68 kilometers, the crater appears oval in shape when observed from Earth because of foreshortening. Its rim is generally circular but irregular, with a notched appearance along the southwest and eastern edges. The rim projects above Mare Frigoris, and a wrinkle ridge trends southeast from the edge for over 100 kilometers.
The interior of Fontenelle features a fractured floor. A low, wide central hill rises at the midpoint, accompanied by rough ground to the west. Nearby, satellite crater Fontenelle D is classified as a concentric, double-walled crater.
East of Fontenelle lies an angular geometric configuration known as Mädler's Square, named after lunar selenographer Johann Mädler. Roughly square in shape, it appears lozenge-shaped due to foreshortening and was noted in many early books concerning the Moon.