Polybius is a

lunar Lunar most commonly means "of or relating to the Moon". Lunar may also refer to: Arts and entertainment * ''Lunar'' (series), a series of video games * "Lunar" (song), by David Guetta * "Lunar", a song by Priestess from the 2009 album ''Prior t ...

impact crater in the southeast part of the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

, and is named after ancient Greek historian

Polybius Polybius (; grc-gre, Πολύβιος, ; ) was a Greek historian of the Hellenistic period. He is noted for his work , which covered the period of 264–146 BC and the Punic Wars in detail. Polybius is important for his analysis of the mixed ...

. It is located to the south-southeast of the larger crater

Catharina Catharina is a feminine given name, the Dutch and Swedish spelling of the name Catherine. In the Netherlands, people use a great number of short forms in daily life, including ''Carine'', ''Catelijne'', ''Cato'', ''Ina'', ''Ineke'', ''Kaat'', ''Kaat ...

, in the area framed by the

Rupes Altai Rupes Altai is an escarpment in the lunar surface that is located in the southeastern quadrant of the Moon's near side. It is named for the Altai Mountains in Asia, and is the most prominent lunar escarpment. The selenographic coordinates of this f ...

scarp. Some distance to the northeast is the Mare Nectaris, with the flooded craters Beaumont and

Fracastorius ''Fracastorius'' is a genus of Asian seed bugs in the tribe Homoeocerini, erected by William Lucas Distant William Lucas Distant (12 November 1845 Rotherhithe – 4 February 1922 Wanstead) was an English entomologist. Biography Early year ...

. The crater rim of Polybius appears slightly distended in the northeast, and has a cut through the northern wall. But the wall is otherwise moderately intact with only minor erosion. The interior floor is flat and almost featureless, with no central rise. To the south and east, a

ray Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science and mathematics * Ray (geometry), half of a line proceeding from an initial point * Ray (g ...

from Tycho cuts across the bowl-shaped Polybius A and Polybius B craterlets.

Satellite craters

By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Polybius. Polybius K is sometimes referred to as "Larrieu’s Dam" because the unusually straight northwest rim of the crater creates the appearance of a

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, a ...

under certain lighting conditions.''‘Larrieu’s Dam’; the ‘rediscovery’ of a seldom explored topographical lunar feature in the foothills of the Rupes Altai''. Nigel Longshaw. J. Br. Astron. Assoc. 118, 2, 2008. Polybius K crater 4084 h1.jpg, Polybius K crater

References

* * * * * * * * * * * {{Commons category Impact craters on the Moon