Editing Phobos (moon) (section)

== Discovery and etymology ==
{{Main|Moons of Mars#History|l1=History of the moons of Mars}}
Phobos was discovered by the American astronomer [[Asaph Hall]] on 18 August 1877 at the [[United States Naval Observatory]] in [[Washington, D.C.]], at about 09:14 [[Greenwich Mean Time]]. (Contemporary sources, using the pre-1925 [[astronomical day|astronomical convention]] that began the day at noon,<ref name='Campbell "Beginning"'>{{cite journal|last=Campbell|first=W.W.|title=The Beginning of the Astronomical Day |journal=Publications of the Astronomical Society of the Pacific |volume=30 |issue=178 |page=358 |bibcode=1918PASP...30..358C |year=1918 |doi=10.1086/122784|doi-access=free}}</ref> give the time of discovery as 17 August at 16:06 [[Washington Mean Time]], meaning 18 August 04:06 in the modern convention.)<ref>{{Cite journal |url=http://adsabs.harvard.edu//full/seri/Obs../0001//0000181.000.html |title=Notes: The Satellites of Mars |journal=The Observatory |volume=1 |issue=6 |date=20 September 1877 |pages=181–185 |access-date=4 February 2009 |bibcode = 1877Obs.....1..181. }}</ref><ref>{{Cite journal |url=http://adsabs.harvard.edu//full/seri/AN.../0091//0000013.000.html |title=Observations of the Satellites of Mars |last=Hall |first=Asaph |journal=Astronomische Nachrichten |volume=91 |issue=2161 |pages=11/12–13/14 |date=17 October 1877 |type=Signed 21 September 1877 |bibcode = 1877AN.....91...11H |doi=10.1002/asna.18780910103 }}</ref><ref name="Morley1989">{{Cite journal |last=Morley |first=Trevor A. |url=http://adsabs.harvard.edu//full/seri/A+AS./0077//0000220.000.html |title=A Catalogue of Ground-Based Astrometric Observations of the Martian Satellites, 1877–1982 |journal=Astronomy and Astrophysics Supplement Series |volume=77 |issue=2 |date=February 1989 |pages=209–226 |bibcode=1989A&AS...77..209M }} (Table II, p. 220: first observation of Phobos on 18 August 1877.38498)</ref> Hall had discovered [[Deimos (moon)|Deimos]], Mars' other moon, a few days earlier.<ref>{{Citation| title    =Mars Moons: Facts| date =15 November 2017| publisher =NASA| url =https://science.nasa.gov/mars/moons/facts/| archive-url  =https://web.archive.org/web/20231128210959/https://science.nasa.gov/mars/moons/facts/| archive-date =28 November 2023}}</ref>
The discoveries were made using the world's largest [[refracting telescope]], the 26-inch "Great Equatorial".<ref name="Usn">{{cite web |title=Descendants of Asaph Hall Present Memorabilia to USNO: Asaph Hall and the Moons of Mars |url=http://www.usno.navy.mil/hallmedal.html |publisher=USNO Public Affairs Office |access-date=15 October 2024 |archive-url=https://web.archive.org/web/20081204114657/http://www.usno.navy.mil/hallmedal.html |archive-date=4 December 2008 |date=2000}}</ref>

The names, originally spelled ''Phobus'' and ''Deimus'' respectively, were suggested by the British academic [[Henry George Madan|Henry Madan]], a science master at [[Eton College]], who based them on [[Greek mythology]], in which [[Phobos (mythology)|Phobos]] is a companion to the god, [[Ares]].<ref>{{Cite journal |last=Madan |first=Henry George |url=https://books.google.com/books?id=fC4CAAAAYAAJ&pg=RA4-PA475 |journal=Nature |volume=16 |issue=414 |title=Letters to the Editor: The Satellites of Mars |date=4 October 1877 |type=Signed 29 September 1877 |page=475 |doi=10.1038/016475b0 |bibcode=1877Natur..16R.475M |s2cid=3998209 |doi-access=free }}</ref><ref>{{Cite journal |last=Hall |first=Asaph |url=http://adsabs.harvard.edu//full/seri/AN.../0092//0000031.000.html |journal=Astronomische Nachrichten |volume=92 |issue=2187 |title=Names of the Satellites of Mars |date=14 March 1878 |type=Signed 7 February 1878 |pages=47–48 |doi=10.1002/asna.18780920304 |bibcode=1878AN.....92...47H }}</ref>

Planetary moons other than Earth's were never given symbols in the astronomical literature. Denis Moskowitz, a software engineer who designed most of the [[dwarf planet]] symbols, proposed a Greek [[phi]] (the initial of Phobos) combined with Mars' spear as the symbol of Phobos ([[File:Phobos symbol (fixed width).svg|16px]]). This symbol is not widely used.<ref name=moons>{{cite web |url=https://www.unicode.org/L2/L2025/25079-phobos-and-deimos.pdf |title=Phobos and Deimos symbols |last1=Bala |first1=Gavin Jared |last2=Miller |first2=Kirk |date=7 March 2025 |website=unicode.org |publisher=The Unicode Consortium |access-date=14 March 2025 |quote=}}</ref>