Editing Shadow (section)

== Astronomy ==
[[File:Three moons and their shadows parade across Jupiter.jpg|thumb|Three moons ([[Callisto (moon)|Callisto]], [[Europa (moon)|Europa]] and [[Io (moon)|Io]]) and their shadows parade across [[Jupiter]].<ref>{{cite web|title=March of the moons|url=http://www.spacetelescope.org/news/heic1504/|access-date=24 June 2015|url-status=live|archive-url=https://web.archive.org/web/20150728173551/http://www.spacetelescope.org/news/heic1504/|archive-date=28 July 2015}}</ref>]]
The names [[umbra, penumbra and antumbra]] are often used for the shadows cast by [[astronomical object]]s, though they are sometimes used to describe levels of darkness, such as in sunspots. An astronomical object casts human-visible shadows when its [[apparent magnitude]] is equal or lower than -4.<ref>[https://web.archive.org/web/20070627044109/http://www.gsfc.nasa.gov/scienceques2005/20060406.htm NASA Science Question of the Week]. Gsfc.nasa.gov (7 April 2006). Retrieved on 26 April 2013.</ref> The only astronomical objects able to project visible shadows onto Earth are the [[Sun]], the [[Moon]], and in the right conditions, [[Venus]] or [[Jupiter]].<ref>{{cite web |url=http://blogs.discovermagazine.com/badastronomy/2011/11/18/young-astronomer-captures-a-shadow-cast-by-jupiter/#.UaDO1UAoNAU |title=Young astronomer captures a shadow cast by Jupiter : Bad Astronomy |publisher=Blogs.discovermagazine.com |date=18 November 2011 |access-date=27 May 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130702142010/http://blogs.discovermagazine.com/badastronomy/2011/11/18/young-astronomer-captures-a-shadow-cast-by-jupiter#.UaDO1UAoNAU |archive-date=2 July 2013 }}</ref><ref> {{cite journal |url= https://adsabs.harvard.edu/full/1906PA.....14..123D |access-date=21 May 2024 |bibcode=1906PA.....14..123D |title=Jupiter casting a Shadow |last1=Duncan |first1=J. C. |journal=Popular Astronomy |date=1906 |volume=14 |page=123 }}</ref> [[Night]] is caused by the hemisphere of a planet [[daytime|facing its orbital star]] blocking its sunlight.

A shadow cast by the Earth onto the Moon is a [[lunar eclipse]]. Conversely, a shadow cast by the Moon onto the Earth is a [[solar eclipse]].<ref>{{Cite web|url=https://www.moonconnection.com/lunar_vs_solar.phtml|title=Lunar Eclipse vs Solar Eclipse|website=www.moonconnection.com|access-date=27 November 2019}}</ref>