View source for Astronomy:Copernicus (Martian crater)

{{short description|Crater on Mars}}

{{Infobox crater data
| titlecolor  = #FA8072
| title       = Copernicus Crater
| image       = Copernicus, Mars (THEMIS).png
| caption     = A daytime infrared image mosaic from the [[Engineering:Thermal Emission Imaging System|Thermal Emission Imaging System]] (THEMIS) instrument of the [[Astronomy:2001 Mars Odyssey|2001 Mars Odyssey]] spacecraft
| coordinate_title = [[Astronomy:Mars#Geography|Coordinates]]
| globe       = Mars
| coordinates = {{coord|48.8|S|168.8|W|globe:mars_type:landmark|display=inline,title}}
| diameter    = c. 300 km
| eponym      = [[Biography:Nicolaus Copernicus|Nicolaus Copernicus]]
}}
[[File:Copernicus crater 088a35.jpg|thumb|right|240px|[[Engineering:Viking program|Viking 1]] image of Copernicus (right)]]
'''Copernicus''' is a large [[Astronomy:Impact crater|crater]] on [[Astronomy:Mars|Mars]], with a diameter close to 300&nbsp;km. It is located south of the planet's equator in the heavily cratered highlands of [[Astronomy:Terra Sirenum|Terra Sirenum]] in the [[Astronomy:Phaethontis quadrangle|Phaethontis quadrangle]] at 48.8°S and 191.2°E.<ref>{{cite web|title=Gazetteer of Planetary Names|url=http://planetarynames.wr.usgs.gov/Feature/1297}}</ref>  Its name was approved in 1973, and it was named after [[Biography:Nicolaus Copernicus|Nicolaus Copernicus]].

== Description ==
The impact that formed Copernicus likely occurred more than 3 billion years ago. The crater contains smaller craters within its basin and is particularly notable for [[Earth:Gully|gully]] formations that are presumed to be indicative of past liquid water flows.  Many small channels exist in this area; they are further evidence of liquid water.  On the basis of their form, aspects, positions, and location amongst and apparent interaction with features thought to be rich in water ice, many researchers believed that the processes carving the gullies involve liquid water. However, this remains a topic of active research.  
As soon as gullies were discovered,<ref name="Malin, M. 2000">Malin, M., Edgett, K.  2000.  Evidence for recent groundwater seepage and surface runoff on Mars. Science 288, 2330–2335.</ref> researchers began to image many gullies over and over, looking for possible changes.  By 2006, some changes were found.<ref>Malin, M., K. Edgett, L. Posiolova, S. McColley, E. Dobrea.  2006.  Present-day impact cratering rate and contemporary gully activity on Mars.  Science 314, 1573_1577.</ref>  Later, with further analysis it was determined that the changes could have occurred by dry granular flows rather than being driven by flowing water.<ref>Kolb, et al.  2010.  Investigating gully flow emplacement mechanisms using apex slopes.  Icarus 2008, 132-142.</ref><ref>McEwen, A. et al.  2007.  A closer look at water-related geological activity on Mars.  Science 317, 1706-1708.</ref><ref>Pelletier, J., et al.  2008.  Recent bright gully deposits on Mars wet or dry flow?  Geology 36,  211-214.</ref> With continued observations many more changes were found  in [[Astronomy:Gasa (crater)|Gasa]] Crater and others.<ref>NASA/Jet Propulsion Laboratory. "NASA orbiter finds new gully channel on Mars." ScienceDaily. ScienceDaily, 22 March 2014. https://www.sciencedaily.com/releases/2014/03/140322094409.htm</ref>  
With more repeated observations, more and more changes have been found; since the changes occur in the winter and spring, experts are tending to believe that gullies were formed from dry ice. Before-and-after images demonstrated the timing of this activity coincided with seasonal carbon-dioxide frost and temperatures that would not have allowed for liquid water.  When dry ice frost changes to a gas, it may lubricate dry material to flow especially on steep slopes.<ref>{{Cite web|url=http://www.jpl.nasa.gov/news/news.php?release=2014-226|title=NASA Spacecraft Observes Further Evidence of Dry Ice Gullies on Mars|website=[[Organization:Jet Propulsion Laboratory|Jet Propulsion Laboratory]]}}</ref><ref>{{Cite web|url=http://hirise.lpl.arizona.edu/ESP_032078_1420|title=HiRISE &#124; Activity in Martian Gullies (ESP_032078_1420)}}</ref><ref>{{Cite web|url=http://www.space.com/26534-mars-gullies-dry-ice.html|title = Gullies on Mars Carved by Dry Ice, Not Water|website = Space.com|date = 16 July 2014}}</ref>  In some years frost, perhaps as thick as 1 meter.

== Dust devil tracks ==

Many areas on Mars experience the passage of giant dust devils. A thin coating of fine bright dust covers most of the [[Astronomy:Martian surface|Martian surface]].  When a dust devil goes by it blows away the coating and exposes the underlying dark surface.  Dust devils have been seen from the ground and high overhead from orbit. They have even blown the dust off of the solar panels of the two Rovers on Mars, thereby greatly extending their lives.<ref>{{cite web | url=http://marsrovers.jpl.nasa.gov/gallery/press/spirit/20070412a.html | title=Mars Exploration Rover }}</ref>  The twin Rovers were designed to last for 3 months, instead they have lasted for years and are still going. Opportunity Rover has lasted over 10 years and is still sending back data as of August 2017.   The pattern of the tracks have been shown to change every few months.<ref>{{Cite web |url=http://mars.jpl.nasa.gov/spotlight/KenEdgett.html |title=Mars Exploration: Features |access-date=2017-08-14 |archive-url=https://web.archive.org/web/20111028015730/http://mars.jpl.nasa.gov/spotlight/kenEdgett.html |archive-date=2011-10-28 |url-status=dead }}</ref>

== Gallery ==
<gallery class="center" widths="190" heights="180">
File:Wikicopernicus.jpg|Eastern edge of '''Copernicus Crater (Martian Crater)''', as seen by CTX camera (on [[Astronomy:Mars Reconnaissance Orbiter|Mars Reconnaissance Orbiter]]).
File:Wikicopernicusdevils.jpg|[[Astronomy:Dust devil tracks|Dust devil tracks]] on floor of Copernicus Crater, as seen by CTX camera (on Mars Reconnaissance Orbiter).  Note: this is an enlargement of the previous image of the eastern edge of Copernicus.
File:Wikicopernicusgullies.jpg|Gullies in small crater on rim of Copernicus Crater, as seen by CTX camera (on Mars Reconnaissance Orbiter).   Note: this is an enlargement of a previous image of the eastern edge of Copernicus.
File:Wikicopernicuschannels.jpg|Channels on the floor of Copernicus Crater, as seen by CTX
File:Wikicopernicusdikes.jpg|Possible dikes on floor of Copernicus Crater, as seen by CTX camera (on Mars Reconnaissance Orbiter).  The straight lines may be dikes, faults, or joints.
File:Copernicus crater.jpg|This topographic map was created using Mars Orbiter Laser Altimeter (MOLA) technology on the Mars Global Surveyor spacecraft. This image is a screenshot of RedMapper's website and shows the geographical position of Copernicus crater within the Terra Sirenum region of Mars.
File:ESP 031221 1315-Mars-CopernicusCrater-OlivineDuneTerrain-20190831.jpg|Copernicus crater<br />[[Chemistry:Olivine|olivine]] sand dune terrain.
</gallery>

== See also ==
* [[Astronomy:List of craters on Mars|List of craters on Mars]]

== References ==
{{reflist}}

== External links ==
* [https://www.google.com/mars/#lon=-113.203125&q=Newton%20crater Google Mars linked to the Newton Crater]
* {{APOD |date=26 June 2000 |title=Newton Crater: Evidence for Recent Water on Mars}}
* [http://www.msss.com/mars_images/moc/june2000/newton/index.html Newton Crater]
* [http://www.solarviews.com/cap/mgs/PIA01039.htm Solar Views]

{{Geography of Mars}}

[[Category:Impact craters on Mars]]
[[Category:Phaethontis quadrangle]]

{{Sourceattribution|Copernicus (Martian crater)}}