Neper (crater) explained

Coordinates:	8.8°N 84.5°W
Diameter:	137 km (85 miles)
Depth:	2.0 km
Colong:	343
Eponym:	John Napier

Neper is an old lunar impact crater located near the eastern limb of the Moon. Due to its location the crater must be viewed during a suitable libration, and is very foreshortened. The crater lies on the south edge of Mare Marginis, to the east of the crater Jansky. To the northwest across the Mare Marginis is the crater Goddard.

The crater inner walls have worn terraces, with low rim edges at the northern and southern extremes. The crater floor is dark and flat, with a central peak and several crater impacts near the west rim. The most notable of these is a small crater near the north-northwestern edge.

It is named after the Scottish mathematician, physicist, astronomer and astrologer John Napier.

Neper is one of the largest craters of Nectarian age.^[1]

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 Neper.

Neper	Latitude	Longitude	Diameter
D	9.2° N	80.8° E	40 km
H	10.4° N	78.2° E	9 km
Q	8.0° N	83.1° E	12 km

The following craters have been renamed by the IAU.

• Neper G - See Virchow (crater).
• Neper K - See Tacchini (crater).

References

• News: Gladstone-Millar . Lynne . March 29, 2003 . Forgotten genius still burns bright . . 2007-09-06.

• Book: Andersson . L. E. . Whitaker . E. A. . Ewen Whitaker . 1982 . NASA Catalogue of Lunar Nomenclature . NASA RP-1097 .
• Web site: Blue . Jennifer . July 25, 2007 . Gazetteer of Planetary Nomenclature . . 2007-08-05 .
• Book: Bussey . B. . Ben Bussey . Spudis . P. . Paul Spudis . 2004 . The Clementine Atlas of the Moon . . New York . 978-0-521-81528-4 .
• Book: Cocks . Elijah E. . Cocks . Josiah C. . 1995 . Who's Who on the Moon: A Biographical Dictionary of Lunar Nomenclature . Tudor Publishers . 978-0-936389-27-1 .
• Web site: McDowell . Jonathan . July 15, 2007 . Lunar Nomenclature . . 2007-10-24 .
• Menzel. D. H.. Minnaert. M.. Levin. B.. Dollfus. A.. Bell. B.. Report on Lunar Nomenclature by the Working Group of Commission 17 of the IAU. 10.1007/BF00171763. Space Science Reviews. 12. 2. 136–186. 1971. 1971SSRv...12..136M. 122125855.
• Book: Moore , Patrick . Patrick Moore . 2001 . On the Moon . . 978-0-304-35469-6 .
• Book: Price , Fred W. . 1988 . The Moon Observer's Handbook . Cambridge University Press . 978-0-521-33500-3 .
• Book: Rükl , Antonín . Antonín Rükl . 1990 . Atlas of the Moon . . 978-0-913135-17-4 .
• Book: Webb , Rev. T. W. . Thomas William Webb . 1962 . Celestial Objects for Common Telescopes . 6th revised . Dover . 978-0-486-20917-3 .
• Book: Whitaker , Ewen A. . Ewen Whitaker . 1999 . Mapping and Naming the Moon . Cambridge University Press . 978-0-521-62248-6 .
• Book: Wlasuk , Peter T. . 2000 . Observing the Moon . Springer . 978-1-85233-193-1 .

Notes and References

1. https://pubs.er.usgs.gov/publication/pp1348 The geologic history of the Moon