What is Phobos (moon)?
{{Infobox Planet | name = Phobos | image = Phobos colour 2008.jpg | caption = Enhanced-color view of Phobos obtained by ''[[Mars Reconnaissance Orbiter]]'' on March 23 2008. | bgcolour = #ffc0c0 | discoverer = [[Asaph Hall]] | discovered = August 18, 1877 | epoch = [[J2000]] | semimajor = {{gaps|9|377.2}} km<ref>{{Cite web |url=http://exp.arc.nasa.gov/downloads/celestia/data/solarsys.ssc |title=NASA Celestia |access-date=2009-09-07 |archive-date=2005-03-09 |archive-url=https://web.archive.org/web/20050309115746/http://exp.arc.nasa.gov/downloads/celestia/data/solarsys.ssc |url-status=dead }}</ref> | eccentricity = {{gaps|0.015|1}} | periapsis = {{gaps|9|235.6}} km | apoapsis = {{gaps|9|518.8}} km | period = {{gaps|0.318|910|23}} [[day|d]]<br/>(7 [[hour|h]] 39.2 [[minute|min]]) | avg_speed = 2.138 km/[[second|s]] | inclination = 1.093[[degree (angle)|°]] (to Mars's equator)<br/>0.046° (to local [[Laplace plane]])<br/>26.04° (to the [[ecliptic]]) | satellite_of = [[Mars]] | mean_radius = 11.1 km<ref name=jplssd>{{cite web |url=http://ssd.jpl.nasa.gov/?sat_phys_par |publisher=[[JPL]] (Solar System Dynamics) |title=Planetary Satellite Physical Parameters |date=2006-07-13 |accessdate=2008-01-29}}</ref><br/>({{gaps|0.002|1}} [[Earth]]s) | dimensions = 26.8 &times; 22.4 &times; 18.4 km<ref name=NASA>{{cite web |date=2003-09-30 |title=Mars: Moons: Phobos |publisher=NASA Solar System Exploration |url=http://solarsystem.nasa.gov/planets/profile.cfm?Object=Mar_Phobos |accessdate=2008-08-18 |archive-date=2014-06-24 |archive-url=https://web.archive.org/web/20140624191709/https://solarsystem.nasa.gov/planets/profile.cfm?Object=Mar_Phobos |url-status=dead }}</ref> | surface_area = {{gaps|~6|100}} km²<br/>(11.9 [[micro|µ]]Earths) | volume = {{gaps|5|680}} [[cubic kilometre|km³]]<ref name=dlr2008>{{cite web |url=http://www.d