Herschel Crater Appears As Dot Eaten by Pac-Man in Mimas Temperature Map

Summary: A Mimas temperature map shows unexpected coldness around Herschel Crater, according to data obtained Feb. 13, 2010, by Cassini-Huygens spacecraft.

Detail of Mysterious Temperatures on Mimas, released March 29, 2010, shows pareidolic Pac-Man and Pac-Dot images of Saturnian moon Mimas and its dominant crater, Herschel, in temperature map (above) created from data gathered Feb. 13, 2010, by the Cassini-Huygens spacecraft’s composite infrared spectrometer (CIRS); lower image incorporates temperature map into mosaic of images captured on previous flybys: courtesy NASA / JPL (Jet Propulsion Laboratory) / SWRI (Southwest Research Institute) / SSI (Space Science Institute), via NASA Goddard Space Flight Center (GSFC) pages

Herschel Crater appears as a dot eaten by Pac-Man in a Mimas temperature map created by data gathered during the Cassini-Huygens spacecraft’s closest-ever approach of the Saturnian moon on Feb. 13, 2010.

“The highest-resolution-yet temperature map and images of Saturn’s icy moon Mimas obtained by NASA’s Cassini spacecraft reveal surprising patterns on the surface of the small moon, including unexpected hot regions that resemble ‘Pac-Man’ eating a dot, and striking bands of light and dark in crater walls,” writes Robert Garner, lead web editor at the National Aeronautics and Space Administration’s (NASA) Goddard Space Flight Center (GSFC) in Greenbelt, Maryland, in his March 29, 2010, feature for the NASA GSFC webpage.

The data from Cassini-Huygens spacecraft’s composite infrared spectrometer (CIRS) defied GSFC scientists’ expectations of smooth temperature variations with an early afternoon peak near the moon’s equator. Instead, the CIRS-generated map identifies a morning peak, color coded in yellows (warmest), oranges and reds, along the moon’s trailing edge. Colder temperatures, color coded in purples and blues (coldest), prevail to the peak’s east, in the moon’s leading hemisphere dominated by equator-straddling Herschel Crater. Garner gives a temperature range with the highest at around 77 Kelvin (minus 294 degrees Fahrenheit) and the lowest at around 77 Kelvin (minus 320 degrees Fahrenheit).

The sharply defined peak’s sidewise v-shape, which radiates from the equator to encompass both polar regions, resembles Pac-Man’s wide open mouth. Hershel Crater poises motionless, as a doomed Pac-Dot, in front of Pac-Man’s mouth, midway between the maze arcade game hero’s greatly extended jaws.

Herschel Crater stands out as a mainly purplish circle against a bluish background of colder temperatures. Oppositely extreme temperatures, positioned oppositely on a diagonal axis through the crater’s central peaks, interrupt the crater’s overall purplishness. A bluish dot of colder temperatures lies inside the crater’s northwestern rim. An orangish-reddish dot sits as a pocket of warmer temperatures inside the crater’s southeastern rim.

“Even though we can’t explain the observed pattern of surface temperatures on Mimas, the giant Herschel crater is a leading suspect,” reports Michael Flasar, NASA Goddard Space Flight Center’s composite infrared spectrometer (CIRS) principal investigator. “The energy of impact that created it several billion years ago has been estimated to be one-seventh of Mimas’s own gravitational energy. Anything much larger would likely have torn the moon apart. We really would like to see if there is an anomalous temperature pattern on the other side of Herschel, which has been observed so closely.”

Herschel Crater’s tall walls help to explain the generally warmer temperatures within the crater. Herschel’s 5-kilometer- (3-mile-) high walls operate as heat traps for the crater’s interior.

Warmer temperatures also characterize Herschel Crater’s environs. The composite infrared spectrometer’s temperature map reveals purplish regions extending outward from the crater, especially from the western, eastern and southern portions of the rim.

Yet the temperature map baffles its interpreters. “We suspect the temperatures are revealing differences in texture on the surface,” observes John Spencer, a CIRS co-investigator based at Southwest Research Institute in Boulder, Colorado. “It’s maybe something like the difference between old, dense snow and freshly fallen powder.”

Garner explains that denser ice’s quick conduction of the sun’s heat away from the surface accounts for daytime coldness in icy areas. Powdery ice’s insulating ability promotes warmed surfaces by trapping solar heat at the surface.

Spencer suspects that a much higher thermal inertia exists in Mimas’ colder regions, according to an interview posted March 30, 2010, on NASA Science Mission Directorate’s Solar System Exploration website by Cassini lead propulsion engineer Todd J. Barber. “In this case,” writes Barber, “heat could soak into the Mimas interior more easily rather than raise the temperature of the surface. The shocking inference is that the thermal conductivity has to be at least ten times greater in the cold regions vs. the warmer regions . . .”

Garner reports Spencer’s observation that, even with the surface texture variation hypothesis, scientists are still struggling to understand the Mimas temperature map’s sharp regional boundaries. The impact that excavated Herschel Crater could have melted surface ice, which created a watery expanse that subsequently became a flash-frozen, hard surface. Nevertheless, Spencer points out the puzzling presence of an intact, dense top layer that already should have been pulverized by meteorites and other space debris.

The takeaway for Herschel Crater’s appearance as a dot eaten by Pac-Man in a Mimas temperature map is that the data gathered Feb. 13, 2010, by the Cassini-Huygens spacecraft’s composite infrared spectrometer (CIRS) created a temperature map that resembles a gameplay of the Pac-Man video game franchise, with Pac-Man’s jaws representing the map’s warmest temperatures and Herschel Crater’s Pac-Dot depicting an oasis of less cold temperatures within the map’s coldest region.

Pac-Man, a maze arcade game developed and released May 22, 1980, in Japan and Oct. 10, 1980, in North America, makes a pareidolic appearance in a Cassini-Huygens spacecraft-generated temperature map of Saturnian moon Mimas: PAC-MAN @pacman, via Facebook Feb. 6, 2009

Acknowledgment

My special thanks to talented artists and photographers/concerned organizations who make their fine images available on the internet.

Image credits:

Detail of Mysterious Temperatures on Mimas, released March 29, 2010, shows pareidolic Pac-Man and Pac-Dot images of Saturnian moon Mimas and its dominant crater, Herschel, in temperature map (above) created from data gathered Feb. 13, 2010, by the Cassini-Huygens spacecraft’s composite infrared spectrometer (CIRS); lower image incorporates temperature map into mosaic of images captured on previous flybys: courtesy NASA / JPL (Jet Propulsion Laboratory) / SWRI (Southwest Research Institute) / SSI (Space Science Institute), via NASA Goddard Space Flight Center (GSFC) pages @ https://www.nasa.gov/centers/goddard/news/features/2010/pac-man-mimas.html

Pac-Man, a maze arcade game developed and released May 22, 1980, in Japan and Oct. 10, 1980, in North America, makes a pareidolic appearance in a Cassini-Huygens spacecraft-generated temperature map of Saturnian moon Mimas: PAC-MAN @pacman, via Facebook Feb. 6, 2009, @ https://www.facebook.com/pacman/photos/a.67802275927/67802510927/

For further information:

Barber, Todd J. “Insider’s Cassini: Dr. John Spencer and Unexpected Mimas Temperature Data.” NASA Science Solar System Exploration > News. March 30, 2010.
Available @ https://solarsystem.nasa.gov/news/11176/

Garner, Robert, ed. “Goddard Instrument Aboard Cassini Spacecraft Sees ‘Pac-Man’ on Saturn Moon.” NASA . Centers > Goddard Space Flight Center > News. March 29, 2010.
Available @ https://www.nasa.gov/centers/goddard/news/features/2010/pac-man-mimas.html

Lavoie, Sue, site manager. “PIA 12867: Bizarre Temperatures on Mimas.” NASA Jet Propulsion Laboratory Photojournal. Image added March 29, 2010.
Available @ https://photojournal.jpl.nasa.gov/catalog/PIA12867

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Marriner, Derdriu. “Herschel Crater Vicinity Has Weaker Infrared Brightness Than Mimas Norm.” Earth and Space News. Wednesday, Oct. 26, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/10/herschel-crater-vicinity-has-weaker.html

Marriner, Derdriu. “Mimantean Crater Herschel Displays Subtle Colors in Close Flyby View.” Earth and Space News. Wednesday, Oct. 12, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/10/mimantean-crater-herschel-displays.html

Marriner, Derdriu. “Mimantean Crater Herschel Honors Mimas Discoverer William Herschel.” Earth and Space News. Wednesday, Sept. 7, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/09/mimantean-crater-herschel-honors-mimas.html

Marriner, Derdriu. “Mimantean Crater Herschel Partially Overlies Oeta Chasma.” Earth and Space News. Wednesday, Oct. 5, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/09/mimantean-crater-herschel-partially.html

Marriner, Derdriu. “Mimantean Crater Herschel Reveals Dark Areas in Close Flyby View.” Earth and Space News. Wednesday, Oct. 19, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/10/mimantean-crater-herschel-reveals-dark.html

Marriner, Derdriu. "Mimas Temperature Map Shows Unexpected Coldness Around Herschel Crater." Earth and Space News. Wednesday, Nov. 2, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/10/mimas-temperature-map-shows-unexpected.html

Marriner, Derdriu. “William Herschel Discovered Mimas With Newly Built 40-Foot Telescope.” Earth and Space News. Wednesday, Sep. 21, 2019.
Available @ https://earth-and-space-news.blogspot.com/2011/09/william-herschel-discovered-mimas-with.html

Marriner, Derdriu. “William Herschel Discovered Saturnian Moon Mimas Sept. 17, 1789.” Earth and Space News. Wednesday, Sept. 14, 2011.
Available @ https://earth-and-space-news.blogspot.com/2011/09/william-herschel-discovered-saturnian.html

Moore, Patrick, Sir. Philip’s Atlas of the Universe. Revised edition. London UK: Philip’s, 2005.

PAC-MAN @pacman. “Added a new photo.” Facebook. Feb. 6, 2009.
Available @ https://www.facebook.com/pacman/photos/a.67802275927/67802510927/

U.S. Geological Survey. “Preliminary Pictorial Map of Mimas.” Atlas of the Saturnian Satellites. IMAP 1482. Prepared for the Voyager Imaging Team in cooperation with the Jet Propulsion Laboratory, California Institute of Technology and the National Aeronautics and Space Administration. Directed by R.M. (Raymond Milner) Batson / U.S. Geological Survey Branch of Astrogeologic Studies. Airbrush representation by Jay L. Inge. Data preparation and preliminary image processing by K.F. Mullins, Christopher Isbell, E.M. Lee, H.G. Morgan and B.A. Skiff. Reston VA: U.S. Geological Survey, 1982.
Available @ https://pubs.er.usgs.gov/publication/i1489
Available @ http://171.67.35.48/view/6829740

Whatmore, Rebecca, ed. “Bizarre Temperatures on Mimas.” NASA > Mission Pages > Cassini-Huygens Mission to Saturn > Multimedia. March 29, 2010.
Available @ https://www.nasa.gov/mission_pages/cassini/multimedia/pia12867.html