Geological Chronicle
Sinus Roris, named from the Latin for "Bay of Dew," is a dark basaltic plain along the northern edge of Oceanus Procellarum on the lunar near side. Named a sinus because of its small size relative to major lunar seas, the feature spans a registered diameter of 195.04 kilometers and shares the characteristics of lunar maria, having formed when impact craters filled with magma that hardened into smooth plains.
The borders of Sinus Roris are framed along the western edge by the craters Markov and Oenopides, and to the north by Babbage and South. At its eastern edge, the bay joins Mare Frigoris. Terrain where the official coordinates place the bay displays a higher albedo than the mare to the south, most likely due to deposits of ejecta from impacts to the north.
Many selenographers have taken liberties with the dimensions of Sinus Roris, drawing maps that indicate a much larger region than its official boundaries. These maps range west to the craters Gerard and Repsold, east to Harpalus, and south to latitude 44° N, approaching Mons Rümker.
Sinus Roris has also appeared in lunar exploration concepts and science fiction. Early concepts of a Moon landing promoted by Wernher von Braun envisaged establishing a permanent lunar base in the region, leading in modified form to Project Apollo. In 1961, author Arthur C. Clarke set his novel A Fall of Moondust within a fictional Sea of Thirst located in the bay.