Helicon (crater)
{{Short description|Crater on the Moon}}
{{Infobox Lunar crater
| image = Helicon crater 4134 h2.jpg
| image_size =
| caption = Lunar Orbiter 4 image
| coordinates = {{coord|40.4|N|23.1|W|globe:moon_type:landmark|display=inline,title}}
| diameter = 25 km
| depth = 0.5 km
| colong = 23
| eponym = Helicon of Cyzicus
}}
File:Oceanus Procellarum Si Barbero Zetta Ferruggia.jpg
Image:Helicon crater Le Verrier crater AS15-M-1554.jpg (right). The mountain on the horizon at left is Promontorium Laplace, about 180 km beyond Helicon. Note that Helicon's ejecta is buried by the mare lava, but Le Verrier's is not. From Apollo 15.]]
Image:Helicon crater AS15-81-10976.jpg
Helicon is a small lunar impact crater that is located on the north part of the Mare Imbrium. The crater was named after 4th century BC Greek astronomer Helicon of Cyzicus,{{gpn|2424}} a friend and disciple of Plato.{{DGRBM|author=CPM|title=Helicon|volume=2|page=372}} To the northwest is the prominent Sinus Iridum, a mountain-ringed bay on the mare. Just to the east is the slightly smaller crater Le Verrier.
Helicon is a nearly circular formation with inner walls that curve down to a relatively flat floor. There is a tiny craterlet located at the midpoint of the interior, and a small craterlet along the southwestern rim.
Satellite craters
According to convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Helicon.
| class="wikitable"
!width="25%" style="background:#eeeeee;" |Helicon !width="25%" style="background:#eeeeee;" |Latitude !width="25%" style="background:#eeeeee;" |Longitude !width="25%" style="background:#eeeeee;" |Diameter |
| align="center"|B
|align="center"|38.0° N |align="center"|21.3° W |align="center"|6 km |
| align="center"|C
|align="center"|40.1° N |align="center"|26.2° W |align="center"|1 km |
| align="center"|E
|align="center"|40.5° N |align="center"|24.1° W |align="center"|3 km |
| align="center"|G
|align="center"|41.7° N |align="center"|24.9° W |align="center"|2 km |
References
{{Reflist}}
{{refbegin}}
- {{cite book
| last1 = Andersson
| first1 = L. E.
| last2 = Whitaker
| first2 = E. A.
| authorlink2 = Ewen Whitaker
| date = 1982
| title = NASA Catalogue of Lunar Nomenclature
| publisher = NASA RP-1097
}}
- {{cite book
| last1 = Bussey
| first1 = B.
| authorlink1 = Ben Bussey
| last2 = Spudis
| first2 = P.
| authorlink2 = Paul Spudis
| date = 2004
| title = The Clementine Atlas of the Moon
| publisher = Cambridge University Press
| location = New York
| isbn = 978-0-521-81528-4
}}
- {{cite book
| last1 = Cocks
| first1 = Elijah E.
| last2 = Cocks
| first2 = Josiah C.
| date = 1995
| title = Who's Who on the Moon: A Biographical Dictionary of Lunar Nomenclature
| publisher = Tudor Publishers
| isbn = 978-0-936389-27-1
| url = https://archive.org/details/isbn_9780936389271
}}
- {{cite web
| last = McDowell
| first = Jonathan
| date = July 15, 2007
| url = http://host.planet4589.org/astro/lunar/
| title = Lunar Nomenclature
| publisher = Jonathan's Space Report
| access-date = 2007-10-24
}}
- {{cite journal| last1 = Menzel| first1 = D. H.| last2 = Minnaert| first2 = M.| last3 = Levin| first3 = B.| last4 = Dollfus| first4 = A.| last5 = Bell| first5 = B.| title = Report on Lunar Nomenclature by the Working Group of Commission 17 of the IAU| doi = 10.1007/BF00171763| journal = Space Science Reviews| volume = 12| issue = 2| pages = 136–186| date = 1971| bibcode = 1971SSRv...12..136M| s2cid = 122125855}}
- {{cite book
| first = Patrick
| last = Moore
| authorlink = Patrick Moore
| date = 2001
| title = On the Moon
| publisher = Sterling Publishing Co.
| isbn = 978-0-304-35469-6
| url = https://archive.org/details/patrickmooreonmo00patr
}}
- {{cite book
| first = Fred W.
| last = Price
| date = 1988
| title = The Moon Observer's Handbook
| publisher = Cambridge University Press
| isbn = 978-0-521-33500-3
}}
- {{cite book
| last = Rükl
| first = Antonín
| authorlink = Antonín Rükl
| date = 1990
| title = Atlas of the Moon
| publisher = Kalmbach Books
| isbn = 978-0-913135-17-4
}}
- {{cite book
| last = Webb
| first = Rev. T. W.
| authorlink = Thomas William Webb
| date = 1962
| title = Celestial Objects for Common Telescopes
| edition = 6th revised
| publisher = Dover
| isbn = 978-0-486-20917-3
| url = https://archive.org/details/celestialobjects00webb
}}
- {{cite book
| first = Ewen A.
| last = Whitaker
| authorlink = Ewen Whitaker
| date = 1999
| title = Mapping and Naming the Moon
| publisher = Cambridge University Press
| isbn = 978-0-521-62248-6
}}
- {{cite book
| first = Peter T.
| last = Wlasuk
| date = 2000
| title = Observing the Moon
| publisher = Springer
| isbn = 978-1-85233-193-1
}}
{{refend}}
External links
{{Commons category}}
- {{cite web | last = Wood | first = Chuck | date = 2006-08-20 | url = http://www2.lpod.org/wiki/August_20,_2006 | title = Out the Porthole | publisher = Lunar Photo of the Day | access-date = 2016-09-18 }}, excellent earth-based image of Sinus Iridum and vicinity, including Helicon and Le Verrier