Nonius (crater) explained

Nonius is a lunar impact crater. It is located in the rugged southern highlands on the Moon's near side. It was named after 16th century Portuguese mathematician Pedro Nunes, Latinized as Nonius.^[1] The northwestern side and about half the interior floor are overlain by the rim and outer rampart of the walled plain Walther. About half its diameter to the southeast is the smaller crater Kaiser, and slightly farther to the south lies Fernelius.

The surviving rim of this crater has been damaged by multiple impacts, including the merged pair of Nonius K and Nonius L across the northern rim. The surviving outline is more hexagonal in shape than round. The interior floor has an uneven surface, with low ridges and a crater-formed gouge in the western half.

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 Nonius.

Nonius	Latitude	Longitude	Diameter
A	35.4° S	5.6° E	10 km
B	35.8° S	2.0° E	21 km
C	35.4° S	1.1° E	7 km
D	35.5° S	1.8° E	6 km
F	35.9° S	3.8° E	7 km
G	34.7° S	5.7° E	6 km
K	33.7° S	3.9° E	18 km
L	33.5° S	3.5° E	31 km
Q	35.9° S	4.2° E	7 km
R	35.9° S	3.3° E	10 km
S	34.8° S	4.3° E	4 km

References

• Book: Andersson . L. E. . Whitaker . E. A. . Ewen Whitaker . 1982 . NASA Catalogue of Lunar Nomenclature . NASA RP-1097 .
• 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

. 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

. Antonín Rükl . 1990 . Atlas of the Moon . . 978-0-913135-17-4 .

• Book: Webb , Rev. T. W. . Thomas William Webb

. Thomas William Webb . 1962 . Celestial Objects for Common Telescopes . 6th revised . Dover . 978-0-486-20917-3 .

• Book: Whitaker , Ewen A. . Ewen Whitaker

. 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. Web site: Nonius. Gazeteer of Planetary Nomenclature. International Astronomical Union. 7 September 2017.