Helmert (crater)
Helmert is a lunar impact crater at the southern edge of the Mare Smythii. It lies near the eastern limb of the Moon, and from the Earth it is seen nearly from the side. The visibility of this feature can be strongly affected by libration of the Moon in its orbit.
 Apollo 8 Hasselblad camera image | |
| Coordinates | 7.6°S 87.6°E |
|---|---|
| Diameter | 26 km |
| Depth | Unknown |
| Colongitude | 273° at sunrise |
| Eponym | Friedrich R. Helmert |
This crater forms part of a merged pair with the similar crater Kao on its northern side. There is a gap in the rims where these two craters are joined, and the interior floors have been resurfaced by lava, leaving a level surface across the bottom of both craters. This floor is nearly featureless, and has the same low albedo as the dark lunar mare to the north. The outer rim has a small crater joined to the eastern edge of the northern gap, but is otherwise not overlain by any notable craters.
References
- Helmert, Gazetteer of Planetary Nomenclature, International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN)
- Andersson, L. E.; Whitaker, E. A. (1982). NASA Catalogue of Lunar Nomenclature. NASA RP-1097.CS1 maint: ref=harv (link)
- Blue, Jennifer (July 25, 2007). "Gazetteer of Planetary Nomenclature". USGS. Retrieved 2007-08-05.CS1 maint: ref=harv (link)
- Bussey, B.; Spudis, P. (2004). The Clementine Atlas of the Moon. New York: Cambridge University Press. ISBN 978-0-521-81528-4.CS1 maint: ref=harv (link)
- 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.CS1 maint: ref=harv (link)
- McDowell, Jonathan (July 15, 2007). "Lunar Nomenclature". Jonathan's Space Report. Retrieved 2007-10-24.CS1 maint: ref=harv (link)
- 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.CS1 maint: ref=harv (link)
- Moore, Patrick (2001). On the Moon. Sterling Publishing Co. ISBN 978-0-304-35469-6.CS1 maint: ref=harv (link)
- Price, Fred W. (1988). The Moon Observer's Handbook. Cambridge University Press. ISBN 978-0-521-33500-3.CS1 maint: ref=harv (link)
- Rükl, Antonín (1990). Atlas of the Moon. Kalmbach Books. ISBN 978-0-913135-17-4.CS1 maint: ref=harv (link)
- Webb, Rev. T. W. (1962). Celestial Objects for Common Telescopes (6th revised ed.). Dover. ISBN 978-0-486-20917-3.CS1 maint: ref=harv (link)
- Whitaker, Ewen A. (1999). Mapping and Naming the Moon. Cambridge University Press. ISBN 978-0-521-62248-6.CS1 maint: ref=harv (link)
- Wlasuk, Peter T. (2000). Observing the Moon. Springer. ISBN 978-1-85233-193-1.CS1 maint: ref=harv (link)