Palus Somni (

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

''palūs somnī'' "Marsh of Sleep") is an area on the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

of relatively level but somewhat uneven terrain that lies along the northeastern edge of

Mare Tranquillitatis Mare Tranquillitatis (Latin for Sea of Tranquillity or Sea of Tranquility) is a lunar mare that sits within the Tranquillitatis basin on the Moon. It contains Tranquility Base, the first location on another celestial body to be visited by huma ...

and the Sinus Concordiae. It has

selenographic coordinates The selenographic coordinate system is used to refer to locations on the surface of Earth's moon. Any position on the lunar surface can be referenced by specifying two numerical values, which are comparable to the latitude and longitude of Earth ...

14.1° N, 45.0° E, and has a diameter of 163 km. Aldo Ferruggia - Proclus crater

The surface of this feature has low ridges and patches of level terrain. It has a higher

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

than the

lunar mare The lunar maria ( ; mare ) are large, dark, basaltic plains on Earth's Moon, formed by lava flowing into ancient impact basins. They are less reflective than the "highlands" as a result of their iron-rich composition, and hence appear dark to ...

to the west, and is a shade of grey typical of continental terrain. A few minor craters lie within its borders, with the flooded Lyell along the west edge, Crile to the east, and Franz to the northwest. The bright crater

Proclus Proclus Lycius (; 8 February 412 – 17 April 485), called Proclus the Successor (, ''Próklos ho Diádokhos''), was a Greek Neoplatonist philosopher, one of the last major classical philosophers of late antiquity. He set forth one of th ...

is to the northeast. In 1907 it was described as having "a color which is unique upon the moon, a kind of light brown, quite unlike the hue of any of the other plains or mountain regions"Serviss, Garrett P.: ''The Moon.'' 1907.

References

{{Lunar maria Somni, Palus