Editing Moon (section)

===Size and mass===
{{Further|List of natural satellites}}
[[File:Moons of solar system v7.jpg|thumb|upright=1.5|Size comparison of the main moons of the Solar System with Earth to scale. Nineteen moons are large enough [[Hydrostatic equilibrium|to be round]], several having [[subsurface ocean]]s and one, Titan, having a considerable atmosphere.]]
The Moon is by size and mass the fifth largest natural satellite of the Solar System, categorizable as one of its [[planetary-mass moon]]s, making it a satellite planet under the [[geophysical definition of planet|geophysical definitions of the term]].<ref name="Metzger2021">{{Citation |last1=Metzger |first1=Philip |author-link1=Philip T. Metzger |last2=Grundy |first2=Will |last3=Sykes |first3=Mark |last4=Stern |first4=Alan |last5=Bell |first5=James |last6=Detelich |first6=Charlene |last7=Runyon |first7=Kirby |last8=Summers |first8=Michael |date=2021 |title=Moons are planets: Scientific usefulness versus cultural teleology in the taxonomy of planetary science |journal=[[Icarus (journal)|Icarus]] |volume=374 |page=114768 |doi=10.1016/j.icarus.2021.114768 |arxiv=2110.15285 |bibcode=2022Icar..37414768M |s2cid=240071005}}</ref> It is smaller than [[Mercury (planet)|Mercury]] and considerably larger than the largest [[dwarf planet]] of the Solar System, [[Pluto]]. The Moon is the largest natural satellite in the Solar System relative to its [[Primary (astronomy)|primary]] planet.{{efn |There is no strong correlation between the sizes of planets and the sizes of their satellites. Larger planets tend to have more satellites, both large and small, than smaller planets.}}{{efn|name=Moon vs. Charon}}<ref>{{cite web |url=http://www.planetary.org/explore/topics/pluto/ |title=Space Topics: Pluto and Charon |publisher=[[The Planetary Society]] |access-date=April 6, 2010 |url-status=dead |archive-url=https://web.archive.org/web/20120218223842/http://www.planetary.org/explore/topics/pluto/ |archive-date=February 18, 2012}}</ref>

The Moon's diameter is about 3,500&nbsp;km, more than one-quarter of Earth's, with the face of the Moon comparable to the width of either [[mainland Australia]],<ref name="Australia">{{cite web |url=https://theconversation.com/how-big-is-the-moon-let-me-compare-118840 |date=July 18, 2019 |access-date=November 15, 2020 |title=How big is the Moon? |first=Jonti |last=Horner |archive-date=November 7, 2020 |archive-url=https://web.archive.org/web/20201107223707/http://theconversation.com/how-big-is-the-moon-let-me-compare-118840 |url-status=live}}</ref> Europe or the [[contiguous United States]].<ref name="Dyches 2021 d923">{{cite news |last=Dyches |first=Preston |title=Five Things to Know about the Moon |work=NASA Solar System Exploration |date=July 28, 2021 |url=https://solarsystem.nasa.gov/news/1946/five-things-to-know-about-the-moon/ |access-date=September 24, 2023 |archive-date=July 18, 2023 |archive-url=https://web.archive.org/web/20230718090707/https://solarsystem.nasa.gov/news/1946/five-things-to-know-about-the-moon/ |url-status=live}}</ref> The whole surface area of the Moon is about 38&nbsp;million square kilometers, comparable to that of the [[Americas]].<ref name="y857">{{cite magazine |last=Parks |first=Jake |title=Everything you need to know about the Moon |magazine=Astronomy |date=2023-09-07 |url=https://www.astronomy.com/observing/everything-you-need-to-know-about-the-moon/ |access-date=2024-09-09}}</ref><ref name="f708">{{cite web |title=Global Island Explorer |publisher=United States Geological Survey |url=https://rmgsc.cr.usgs.gov/gie/gie.shtml |access-date=2024-09-09 }}{{Dead link|date=April 2025 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>

The Moon's mass is {{frac|1|81}} of Earth's,<ref name="worldbook" /> being the second densest among the planetary moons, and having the second highest [[surface gravity]], after [[Io (moon)|Io]], at {{val |0.1654 |u=[[G-force|g]]}} and an escape velocity of {{convert|2.38|km/s|km/h mph|comma=gaps|abbr=on}}.