Editing Minute and second of arc (section)

==Common examples==
In general, by simple trigonometry, it can be derived that the angle {{tmath|\theta}} [[subtended angle|subtended]] by an object of diameter or length {{tmath|d}} at a distance {{tmath|D}} is given by the following expression:
: <math>\theta = 2\arctan\left(\frac{d}{2D}\right)</math>

One arcminute ({{val|1|u=arcmin}}) is the approximate distance two contours can be separated by, and still be distinguished by, a person with [[visual acuity|20/20 vision]]. The average [[angular diameter|apparent diameter]] of the [[full moon|full Moon]] is about {{val|31|u=arcmin}}, or {{val|0.52|u=deg}}.

One arcsecond ({{val|1|u=arcsec}}) is the angle subtended by:
* a [[Dime (United States coin)|U.S. dime coin]] ({{cvt|0.705|in|mm|disp=semicolon}}) at a distance of {{convert|3.7|km|mi}}<ref>[[Alexei Filippenko|Filippenko, Alex]], ''Understanding the Universe'' (of ''The Great Courses'', on DVD), Lecture 43, time 12:05, The Teaching Company, Chantilly, VA, US, 2007.</ref>
* an object of diameter {{val|725.27|u=km}} at a distance of one [[astronomical unit]] ({{val|149,597,870.7|u=km}})
* an object of diameter {{val|45,866,916|u=km}} at one [[light-year]] ({{val|9,460,730,472,580.8|u=km}})
* an object of diameter one astronomical unit at a distance of one [[parsec]], per the definition of the latter.<ref>{{cite web|title=Cosmic Distance Scales - The Milky Way |website=Imagine the Universe! |url=https://heasarc.gsfc.nasa.gov/docs/cosmic/milkyway_info.html}}</ref>
Also notable examples of size in arcseconds are:
* [[Hubble Space Telescope]] has calculational resolution of 0.05 arcseconds and actual resolution of almost 0.1 arcseconds, which is close to the [[diffraction limit]].<ref name=":0">{{cite web |title=What is the diffraction limit of a telescope? |url=http://www.astro.cornell.edu/academics/courses/astro201/diff_limit.htm |publisher=Cornell University |archive-url=https://web.archive.org/web/20160917063942/http://www.astro.cornell.edu:80/academics/courses/astro201/diff_limit.htm |archive-date=2016-09-17}}</ref>
* At crescent phase, [[Venus]] measures between 60.2 and 66 seconds of arc.<ref name=":0" />

One milliarcsecond ({{val|1|u=mas}}) is about the size of a [[Half dollar (United States coin)|half dollar]] ({{cvt|1.205|in|mm|disp=semicolon}}), seen from a distance equal to that between the [[Washington Monument]] and the [[Eiffel Tower]] (around {{cvt|6,300|km|mi|disp=x| or }}).

One microarcsecond is about the size of a period at the end of a sentence in the Apollo mission manuals left on the Moon as seen from Earth.{{cn|date=March 2025}}

One nanoarcsecond is about the size of a [[Nickel (United States coin)|nickel]] ({{cvt|0.835|in|mm|disp=semicolon}}) on the surface of [[Neptune]] as observed from Earth.