Editing Cirrus cloud (section)

== Other planets ==
[[File:Clouds on Mars (51055621781).jpg|thumb|A composite black-and-white photograph showing cirrus clouds over the surface of [[Mars]]]]
[[File:Neptune clouds.jpg|alt=A composite black-and-white photograph showing cirrus clouds over the surface of Mars|thumb|Cirrus clouds on Neptune, captured during ''[[Voyager 2]]''<nowiki/>'s flyby]]
Cirrus clouds have been observed on several other planets. In 2008, the Martian Lander ''[[Phoenix Lander|Phoenix]]'' took a [[time-lapse]] photograph of a group of cirrus clouds moving across the [[Atmosphere of Mars|Martian sky]] using lidar.<ref name="NASA-photo">{{cite web|url=http://www.nasa.gov/mission_pages/phoenix/images/press/16145-animated.html|title=Clouds Move Across Mars Horizon|date=19 September 2008|access-date=15 April 2011|publisher=[[National Aeronautics and Space Administration]]|work=Phoenix Photographs|archive-date=2 June 2016|archive-url=https://web.archive.org/web/20160602213811/http://www.nasa.gov/mission_pages/phoenix/images/press/16145-animated.html|url-status=live}}</ref> Near the end of its mission, the Phoenix Lander detected more thin clouds close to the north pole of Mars. Over the course of several days, they thickened, lowered, and eventually began snowing. The total precipitation was only a few thousandths of a millimeter. James Whiteway from [[York University]] concluded that "precipitation is a component of the [Martian] [[hydrologic cycle]]".<ref name="MSNBC-Mars-snow">{{cite news |url=http://www.nbcnews.com/id/31713000 |title=How Martian Clouds Create Snowfall |first=Andrea |last=Thompson |newspaper=Space.com |date=2 July 2009 |publisher=[[NBC News]] |access-date=15 April 2011 |archive-date=23 September 2020 |archive-url=https://web.archive.org/web/20200923230037/http://www.nbcnews.com/id/31713000 |url-status=dead }}</ref> These clouds formed during the Martian night in two layers, one around {{convert|4000|m|ft|abbr=on}} above ground and the other at surface level. They lasted through early morning before being burned away by the Sun. The crystals in these clouds were formed at a temperature of {{convert|-65|C|F}}, and they were shaped roughly like ellipsoids 0.127&nbsp;millimeters long and 0.042&nbsp;millimeters wide.<ref>{{harvnb|Whiteway|Komguem|Dickinson|Cook|2009|pp=68–70}}</ref>

On Jupiter, cirrus clouds are composed of [[ammonia]]. When Jupiter's [[South Equatorial Belt]] disappeared, one hypothesis put forward by Glenn Orten was that a large quantity of ammonia cirrus clouds had formed above it, hiding it from view.<ref>{{cite web|url=https://science.nasa.gov/science-news/science-at-nasa/2010/20may_loststripe/|title=Big Mystery: Jupiter Loses a Stripe|date=20 May 2010|last=Phillips|first=Tony|publisher=[[National Aeronautics and Space Administration]]|work=Nasa Headline News – 2010|access-date=15 April 2011|archive-date=20 April 2011|archive-url=https://web.archive.org/web/20110420012725/http://science.nasa.gov/science-news/science-at-nasa/2010/20may_loststripe/|url-status=live}}</ref> NASA's [[Cassini probe]] detected these clouds on Saturn<ref>{{harvnb|Dougherty|Esposito|2009|page=118}}</ref> and thin water-ice cirrus on Saturn's moon [[Titan (moon)|Titan]].<ref>{{cite web|url=http://www.nasa.gov/mission_pages/cassini/whycassini/titan-clouds_prt.htm|title=Surprise Hidden in Titan's Smog: Cirrus-Like Clouds|publisher=[[National Aeronautics and Space Administration]]|date=3 February 2011|work=Mission News|access-date=16 April 2011|archive-date=16 April 2011|archive-url=https://web.archive.org/web/20110416182620/http://www.nasa.gov/mission_pages/cassini/whycassini/titan-clouds_prt.htm|url-status=live}}</ref> Cirrus clouds composed of [[methane]] ice exist on Uranus.<ref>{{cite web|title=Uranus |publisher=Scholastic |url=http://www2.scholastic.com/browse/article.jsp?id=4871 |access-date=16 April 2011 |archive-url=https://web.archive.org/web/20110902053831/http://www2.scholastic.com/browse/article.jsp?id=4871 |archive-date=2 September 2011 }}</ref> On Neptune, thin wispy clouds which could possibly be cirrus have been detected over the [[Great Dark Spot]]. As on Uranus, these are probably methane crystals.<ref>{{harvnb|Ahrens|2006|page=12}}</ref>

[[Infrared cirrus|Interstellar cirrus clouds]] are composed of tiny dust grains smaller than a [[micrometer (unit)|micrometer]] and are therefore not true cirrus clouds, which are composed of frozen crystals.<ref name="bluebook_c1">{{cite book |author=Planck Science Team|title=Planck: The Scientific Programme (''Blue Book'') |id=ESA-SCI (2005)-1 V2 |pages=123–124 |publisher=European Space Agency |url=http://www.rssd.esa.int/SA/PLANCK/docs/Bluebook-ESA-SCI(2005)1_V2.pdf |year=2005|archive-url=https://web.archive.org/web/20131031065018/http://www.rssd.esa.int/SA/PLANCK/docs/Bluebook-ESA-SCI(2005)1_V2.pdf |access-date=8 July 2009|archive-date=31 October 2013 }}</ref> They range from a few [[light year]]s to dozens of light years across. While they are not technically cirrus clouds, the dust clouds are referred to as "cirrus" because of their similarity to the clouds on Earth. They emit infrared radiation, similar to the way cirrus clouds on Earth reflect heat being radiated out into space.<ref>{{harvnb|Koupelis|2010|page=368}}</ref>
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