What is Deimos (moon)?
[[File:Deimos2.jpg|thumb|]] '''Deimos''' (or '''Mars II''') is the smaller [[Satellite (natural)|moon]] of [[Mars (planet)|Mars]]. Its name comes from the Greek word for terror. Its [[orbital period]] is 30.3 hours, which is 1.263 days. Deimos is only 15 kilometers in [[diameter]]. It is covered with [[crater]]s, as [[Earth]]'s moon and other bodies without an [[atmosphere]] are. == Discovery and naming == Deimos was discovered by [[Asaph Hall]] at the [[United States Naval Observatory]] in [[Washington, D.C.]] on 12 August 1877.<ref>{{Cite journal|last=Campbell|first=W. W.|date=1918|title=The Beginning of the Astronomical Day|url=http://iopscience.iop.org/article/10.1086/122784|journal=Publications of the Astronomical Society of the Pacific|language=en|volume=30|issue=178 |pages=358|doi=10.1086/122784|bibcode=1918PASP...30..358C |s2cid=121676646 |issn=0004-6280|via=}}</ref> It is named after the god [[Deimos (mythology)|Deimos]] in [[Greek mythology]], who was one of Mars' sons, and means Panic. == Physical characteristics == Deimos is not spherical with triaxial dimensions of 15 × 12.2 × 11 km.<ref>{{Cite web|title=Deimos, moon of Mars - The Solar System on Sea and Sky|url=http://www.seasky.org/solar-system/mars-deimos.html|access-date=2020-10-25|website=www.seasky.org}}</ref> Deimos is made up of [[rock (geology)|rock]] rich in [[Carbonaceous chondrite|carbonaceous]] [[material]]. It is has lots of [[Crater|craters]].<ref>{{Cite journal|last1=Busch|first1=Michael W.|last2=Ostro|first2=Steven J.|last3=Benner|first3=Lance A.M.|last4=Giorgini|first4=Jon D.|last5=Magri|first5=Christopher|last6=Howell|first6=Ellen S.|last7=Nolan|first7=Michael C.|last8=Hine|first8=Alice A.|last9=Campbell|first9=Donald B.|date=2007|title=Arecibo radar observations of Phobos and Deimos|url=https://linkinghub.elsevier.com/retrieve/pii/S0019103506004039|journal=Icarus|language=en|volume=186|issue=2|pages=581–584|doi=10.1016/j.icarus.2006.11.003|bibcode=2007Icar..186..581B |via=}}</ref> [[Escape velocity]] from Deimos is 5.6 m/s.<r