View source for MarsDial

[[Image:Color target-A8R1 br.jpg|right|thumb|An image of MarsDial]]
[[File:MarsDial and Rock Spirit.png|thumb|MarsDial on ''[[Spirit rover|Spirit]]'' rover on Mars]]
The '''MarsDial''' is a [[sundial]] that was devised for missions to [[Mars]]. It is used to calibrate the [[Pancam|Pancam camera]]s of the Mars landers. MarsDials were placed on the ''[[Spirit (rover)|Spirit]]'' and ''[[Opportunity (rover)|Opportunity]]'' [[Mars Exploration Rover|Mars rovers]], inscribed with the words "Two worlds, One sun" and the word "Mars" in 22 languages.<ref name="pancam.astro.cornell.edu">[http://pancam.astro.cornell.edu/pancam_instrument/about.html About the Pancam and calibration target]</ref> The MarsDial can function as a [[gnomon]], the stick or other vertical part of a sundial.<ref name="mars.nasa.gov">{{Cite web|url=https://mars.nasa.gov/mer/classroom/marsdial/|title=Mars Exploration Rover: Mars for Educators: Roverquest|website=mars.nasa.gov|access-date=2018-02-08}}</ref><ref name=cornell>[http://athena.cornell.edu/kids/sundial.html Cornell University – Sundial]</ref> The length and direction of the shadow cast by the stick allows observers to calculate the time of day.<ref name="mars.nasa.gov"/> The sundial can also be used to tell which way is North, and to overcome the limitations of a magnetic north different from a true north.<ref name="mars.nasa.gov"/>

The sundial design team<ref name="MarsDialScienceDaily">{{cite web |url= https://www.sciencedaily.com/releases/1999/04/990422055433.htm |title= Martian Sundial Designed For 2001 Space Mission Is Unveiled By Bill Nye 'The Science Guy'|work= [[Science Daily]] |date= 22 April 1999 |quote= The sundial design team included [[Jon Lomberg]], an artist and creative consultant to the [[Mauna Kea Observatory|Mauna Kea]] Center for Astronomy Education, Hawaii;  Tyler Nordgren, an artist and astronomer at the [[United States Naval Observatory Flagstaff Station|U.S. Naval Observatory in Flagstaff, Ariz.]];  sundial expert [[Woodruff T. Sullivan III|Woodruff Sullivan]], professor of astronomy at the [[University of Washington]];  Louis Friedman, executive director of the [[Planetary Society]];  [[Cornell University]] astronomers [[Steve Squyres|Steven Squyres]] and [[James F. Bell, III|Jim Bell]];  and [[Bill Nye]], the television writer and host of the public television children's science program, ’Bill Nye The Science Guy’.}}</ref>  included [[Bill Nye]] "The Science Guy," [[space art]]ist [[Jon Lomberg]], and astronomers [[Woodruff T. Sullivan III|Woodruff Sullivan]], [[Steve Squyres]], [[James F. Bell, III|James Bell]] and [[Tyler Nordgren]].  CAD design and drawings were done by Jason Suchman.  The MarsDial was intended to be part [[science outreach]], part calibration target.

[[Curiosity rover|''Curiosity'']] (MSL), the rover which landed on Mars in August 2012, used a spare sundial remaining from the Mars Exploration Rovers.<ref name=popsci>[http://www.popsci.com/science/article/2012-08/how-mars-rover-curiositys-sundial-will-help-rover-see-mars-living-color Rebecca Boyle (2012). “How A Sundial Lets Curiosity See Mars in Living Color”. ''Popular Science'']</ref> It has a new text that reads "Mars 2012" and "To Mars To Explore".<ref name=popsci/>

The ball is the nodus, the post is the gnomon.<ref name="cornell"/> The colors on the corners are for calibrating colors, and the inner circles are in greyscale.<ref name=cornell/> There is a mirrored section on the middle circle to reflect the sky.<ref name=cornell/>

The sundials are also "[[message artifact]]s"{{mdash}}something for future human explorers to find.<ref>[https://www.hawaiitribune-herald.com/2012/08/01/hawaii-news/big-island-artists-art-to-land-on-mars-again/ ''Hawaii Tribune Herald'' “Big Island artist’s art to land on Mars, again”]</ref>

==Time-lapse==
[[File:Mars Analemma Time Lapse Opportunity.webm|thumb|left|300px|[[Time-lapse]] video of an [[analemma]] from Mars, plotting the course of the Sun over a Martian year (about two Earth years)]]
{{Clear}}

==List==
*[[Spirit (rover)|MER-A ''Spirit'']]<ref name="pancam.astro.cornell.edu"/>
*[[Opportunity (rover)|MER-B ''Opportunity'']]<ref name="pancam.astro.cornell.edu"/>
*[[Curiosity (rover)|MSL ''Curiosity'']]<ref name="popsci"/>

==See also==
*[[Phoenix (spacecraft)#Phoenix DVD]] (''Phoenix'' Mars lander has a DVD)
*[[Voyager Golden Record]]

==References==
{{Reflist}}

==External links==
* [http://www.planetary.org/blogs/bill-nye/20120813-curiositys-marsdial-is-on.html ''Curiosity''{{'}}s Marsdial is on Mars] (The Planetary Society)
* [https://web.archive.org/web/20110528075650/http://planetary.org/programs/projects/marsdial/ The Planetary Society's page covering the MarsDial]
* [https://web.archive.org/web/20150518103822/http://sundials.org/attachments/article/68/MakeYourMarsDial_NyeLabs.PDF Make your own MarsDial!] also [http://www.planetary.org/explore/projects/earth-dial/instructions.pdf Planetary.org instructions] {{Webarchive|url=https://web.archive.org/web/20160304192937/http://www.planetary.org/explore/projects/earth-dial/instructions.pdf |date=2016-03-04 }}
* [http://mars.jpl.nasa.gov/msl/multimedia/raw/?rawid=0003ML0000140000E1_DXXX&s=3 MSL's sundial on Mars]

{{NASAMER}}
{{MSL}}
{{Mars 2020}}
{{Mars}}

[[Category:Mars Exploration Rover mission]]
[[Category:Mars Science Laboratory]]
[[Category:Mars 2020]]
[[Category:Sundials]]
[[Category:Message artifacts]]