Lunar Orbiter 4 image of Letronne. Note higher sun angle than the Apollo 16 image above.Another view of eastern Letronne, from Apollo 16
Letronne is the lava-flooded remnant of a lunarimpact crater. It was named after French archaeologist Jean-Antoine Letronne.[1] The northern part of the rim is completely missing, and opens into the Oceanus Procellarum, forming a bay along the southwestern shore. The formation is located to the northwest of the large crater Gassendi.To the west-southwest is the flooded crater Billy, and north-northwest lies the smaller Flamsteed.
The surviving rim of Letronne is now little more than a semi-circular series of ridges. The flooded, broken rim of Winthrop overlies the western wall. The rim is the most intact along the eastern stretch, forming a mountainous promontory into the mare. A small cluster of central rises lie at the midpoint of the crater. The wrinkle ridgeDorsa Rubey traverses the floor from north to south,[2] and outlines a portion of the missing rim. The crater floor is otherwise nearly smooth and relatively free of craterlets, with the exception of Letronne B near the southeast rim.
Letronne is one of the largest craters of Lower (Early) Imbrian age.[3]
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 Letronne.
The following craters have been renamed by the IAU.
^"Letronne (crater)". Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program.
^Map quadrangle LAC-75, Gazetteer of Planetary Nomenclature. USGS Astrogeology Research Program
^The geologic history of the Moon. USGS Professional Paper 1348. By Don E. Wilhelms, John F. McCauley, and Newell J. Trask. U.S. Government Printing Office, Washington: 1987. Table 10.2.
Andersson, L. E.; Whitaker, E. A. (1982). NASA Catalogue of Lunar Nomenclature. NASA RP-1097.
Cocks, Elijah E.; Cocks, Josiah C. (1995). Who's Who on the Moon: A Biographical Dictionary of Lunar Nomenclature. Tudor Publishers. ISBN 978-0-936389-27-1.
McDowell, Jonathan (July 15, 2007). "Lunar Nomenclature". Jonathan's Space Report. Retrieved 2007-10-24.
Menzel, D. H.; Minnaert, M.; Levin, B.; Dollfus, A.; Bell, B. (1971). "Report on Lunar Nomenclature by the Working Group of Commission 17 of the IAU". Space Science Reviews. 12 (2): 136–186. Bibcode:1971SSRv...12..136M. doi:10.1007/BF00171763. S2CID 122125855.