O'Day is a prominent
lunar impact crater
An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal c ...
that is located on the
far side of 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 ...
. It intrudes into the northwestern edge of
Mare Ingenii, and the rim is lower on that side. To the northwest is the crater pair of
Holetschek and
Sierpinski. Southwest of O'Day lies the crater
Seidel. It is named in honour of the American physicist
Marcus O'Day.
The crater rim of
O'Day
O'Day is a surname of Irish origin. Notable people with the surname include:
*Alan O'Day (1940–2013), American singer-songwriter
*Anita O'Day (1919–2006), American jazz singer
* Aubrey O'Day (born 1984), American singer, dancer, actress, songw ...
remains sharp-edged, and the inner wall is
terrace
Terrace may refer to:
Landforms and construction
* Fluvial terrace, a natural, flat surface that borders and lies above the floodplain of a stream or river
* Terrace, a street suffix
* Terrace, the portion of a lot between the public sidewalk a ...
d, especially in the northwestern half away from the
mare
A mare is an adult female horse or other equidae, equine. In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger. In Thoroughbred horse racing, a mare is defined as a female horse more th ...
. A small crater lies across the southern rim, and a tiny craterlet is located in the low inner rim between the crater and the mare. The floor is rough and irregular, with a double-peak at the midpoint.
Due to its prominent rays, O'Day is mapped as part of the
Copernican System.
[The geologic history of the Moon, 1987, Wilhelms, Don E.; with sections by McCauley, John F.; Trask, Newell J. ]USGS
The United States Geological Survey (USGS), founded as the Geological Survey, is an government agency, agency of the United States Department of the Interior, U.S. Department of the Interior whose work spans the disciplines of biology, geograp ...
Professional Paper: 1348. Plate 11: Copernican System
online
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 O'Day.
External links
Lunar Map 103 showing O'Day and surroundings (Regional maps at the
Lunar and Planetary Institute
The Lunar and Planetary Institute (LPI) is a scientific research institute dedicated to study of the Solar System, its formation, evolution, and current state. The Institute is part of the Universities Space Research Association (USRA) and is ...
.)
References
*
*
*
*
*
*
*
*
*
*
*
*
{{DEFAULTSORT:O'day (Crater)
Impact craters on the Moon