First Quarter Friday, Oct. 23, Shows Apollo 16’s Descartes Highlands

Summary: The moon’s first quarter Friday, Oct. 23, shows Apollo 16’s Descartes Highlands as a rugged jumble west of the lunar near side’s Mare Nectaris.

artist’s concept of eastward view of Apollo 16’s Descartes landing site shows Apollo 16 astronauts’ scheduled transverses (white overlay) in the Lunar Roving Vehicle (LRV); Roman numerals for extravehicular activities (EVAs) and Arabic numbers for traverse station stops; illustration by NASA graphic artist Jerry Elmore; NASA ID S72-16940: Public Domain, via NASA NTRS (NASA Technical Reports Server)

The moon’s first quarter Friday, Oct. 23, shows Apollo 16’s Descartes Highlands as a rugged jumble in the south central lunar highlands west of Mare Nectaris, occupying the leading, or right, half of the moon’s near side for Northern Hemisphere moonwatchers.

October’s first quarter phase begins Friday, Oct. 23, at 13:23 Greenwich Mean Time/Coordinated Universal Time (9:23 a.m. Eastern Daylight Time), according to retired NASA astrophysicist Fred Espenak’s AstroPixels website. As the second of four primary phases in the eight-phase lunar cycle, the first quarter phase signifies illumination of half of the lunar near side’s surface, from Earth’s perspective.

The National Aeronautics and Space Administration’s (NASA) Apollo 16 mission safely landed Commander John Watts Young (Sept. 24, 1930-Jan. 5, 2018) and Lunar Module Pilot Charles “Charlie” Moss Duke Jr. (born Oct. 3, 1935) as the ninth and 10th humans to set foot on the moon. Apollo Lunar Module Orion touched down Friday, April 21, 1972, at 02:23:35 Universal Time (Thursday, April 20, at 9:23 p.m. EST), in the Descartes Highlands’ Cayley Plains. Lunar Module Orion settled between “two fresh, young impact craters,” North Ray and South Ray craters, according to the Universities Space Research Association’s (USRA) Lunar and Planetary Institute (LPI).

North Ray Crater is centered at minus 8.82 degrees south latitude, 15.48 degrees east longitude, according to the International Astronomical Union’s (IAU) Gazetteer of Planetary Nomenclature. The southern hemisphere crater's northernmost and southernmost latitudes extend to minus 8.8 degrees south and minus 8.83 degrees south, respectively. As an eastern hemisphere crater, its easternmost and westernmost longitudes reach to 15.5 degrees and 15.47 degrees, respectively. The sharp-rimmed crater’s diameter measures 0.95 kilometers.

South Ray Crater is centered at minus 9.15 degrees south latitude, 15.38 degrees east longitude. As a southern hemisphere crater, its northernmost and southernmost latitudes reach to minus 9.14 degrees south and minus 9.16 degrees south, respectively. As an eastern hemisphere crater, is easternmost and westernmost longitudes extend to 15.39 degrees east and 15.37 degrees east, respectively. The bright-rayed crater has a diameter of 0.7 kilometers.

The two craters framing Orion’s landing site are located on the Cayley Plains. To the east and south of Orion’s touchdown, the jumbled uplands of the Descartes Mountains contrast with the fairly level plains.

The Cayley Plains take their name from Cayley Crater. The small, circular, bowl-shaped crater is centered at 3.94 degrees north latitude, 15.09 degrees east longitude. As a northern hemisphere crater, its northernmost and southernmost latitudes extend to 4.17 degrees north and 3.7 degrees north, respectively. As an eastern hemisphere crater, its easternmost and westernmost longitudes reach to 15.32 degrees east and 14.85 degrees east, respectively. Cayley Crater’s diameter measures 14.2 kilometers. In 1935, the International Astronomical Union approved the crater’s name, which honors British mathematician Arthur Cayley (Aug. 16, 1821-Jan. 26, 1895).

The Descartes Highlands take their name from Descartes Crater. The heavily degraded crater lies about 50 kilometers south of Apollo 16’s landing site. Descartes Crater is centered at minus 11.74 degrees south latitude, 15.67 degrees east longitude. As a southern hemisphere crater, its northernmost and southernmost latitudes reach minus 10.96 degrees south and minus 12.53 degrees south, respectively. As an eastern hemisphere crater, its easternmost and westernmost longitudes extend to 16.47 degrees east and 14.86 degrees east, respectively. The crater’s diameter measures 47.73 kilometers. In 1935, the International Astronomical Union approved the crater’s name, which honors French mathematician and philosopher René Descartes (March 31, 1596-Feb. 11, 1650).

Lunar Module Orion rests about 600 kilometers west of the center of the Nectaris Basin. Mare Nectaris (Sea of Nectar) occupies the basin’s central region. The small, round, dark lava plain is centered at minus 15.19 degrees south latitude, 34.6 degrees east longitude. The southern hemisphere mare’s northernmost and southernmost latitudes reach minus 9.9 degrees south and minus 21.05 degrees south, respectively. As an eastern hemisphere lava plain, its easternmost and westernmost longitudes stretch to 39.68 degrees east and 28.75 degrees east, respectively. Its diameter spans 339.39 kilometers.

The takeaway for the first quarter’s Oct. 23 showing of Apollo 16’s Descartes Highlands is that the ninth and 10th humans to walk on the moon landed in the fairly level Cayley Plains, north of Descartes Crater and west of Mare Nectaris.

Apollo 16 landing site map shows feature names and actual traverse routes; Lunar Module (LM) Orion (center right), North Ray Crater (top right), South Ray Crater(bottom center); hi-resolution scan by Mary Ann Hagar/LPI: NASA/Lunar and Planetary Institute, via NASA History Apollo 16 Image Library

Acknowledgment

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

Image credits:

artist’s concept of eastward view of Apollo 16’s Descartes landing site shows Apollo 16 astronauts’ scheduled transverses (white overlay) in the Lunar Roving Vehicle (LRV); Roman numerals for extravehicular activities (EVAs) and Arabic numbers for traverse station stops; illustration by NASA graphic artist Jerry Elmore; NASA ID S72-16940: Public Domain, via NASA NTRS (NASA Technical Reports Server) @ https://science.ksc.nasa.gov/mirrors/images/images/pao/AS16/10075787.jpg; NASA Johnson Space Center Collection, via NASA Images @ https://nasaimages.lunaimaging.com/luna/servlet/detail/nasaNAS~7~7~34554~138421:Artist-s-concept-of-eastward-view-o; via Apollo Explorer @ http://www.apolloexplorer.co.uk/default.asp?libsrc=/photo/html/AS16/10075787.htm

Apollo 16 landing site map shows feature names and actual traverse routes; Lunar Module (LM) Orion (center right), North Ray Crater (top right), South Ray Crater (bottom center); hi-resolution scan by Mary Ann Hagar/LPI: NASA/Lunar and Planetary Institute, via NASA History Apollo 16 Image Library @ https://history.nasa.gov/alsj/a16/a16psrf6-4.jpg

For further information:

Atchison, Kenneth C. “Apollo 16 Launch April 16.” PASA News Press Release No. 72-64. April 6, 1972.
Available @ https://www.nasa.gov/specials/apollo50th/pdf/A16_PressKit.pdf

Beyer, Ross. “Apollo 16, Footsteps Under High Sun.” NASA ASU (Arizona State University) School of Earth and Space Exploration (SESE) Lunar Reconnaissance Orbiter Camera (LROC). July 8, 2010.
Available via LROC (Lunar Reconnaissance Orbiter Camera) ASU (Arizona State Univerity) SESE (School of Earth and Space Exploration) @ http://lroc.sese.asu.edu/posts/199
Available via NASA LRO @ https://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/lroc-20100708-apollo16.html

Calendar-12.com. “Moon Phases October 2020.” Calendar-12.com > 2020 Moon Calendar.
Available @ https://www.calendar-12.com/moon_calendar/2020/october

Compton, W. (William) David. “Chapter 13 Lunar Exploration Concluded: To the Lunar Highlands: Descartes.” Where No Man Has Gone Before: A History of Apollo Lunar Exploration Missions. NASA Special Publication SP-4214. NASA History Series. 1989.
Available @ https://www.hq.nasa.gov/office/pao/History/SP-4214/ch13-7.html

Consolmagno, Guy; and Dan M. Davis. Turn Left at Orion. Fourth edition. Cambridge UK; New York NY: Cambridge University Press, 2011.

Espenak, Fred. “Phases of the Moon: 2001 to 2020 Greenwich Mean Time (GMT).” AstroPixels > Ephemeris > Moon > Phases of the Moon From 2001 to 2100.
Available @ http://www.astropixels.com/ephemeris/moon/phases2001gmt.html

International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN). “Descartes.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/1498

International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN). “North Ray.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature. Last updated Oct. 25, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/4342

International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN). “South Ray.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature. Last updated Oct. 25, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/5659

International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN). “Mare Nectaris.” USGS Astrogeology Science Center > Gazetteer of Planetary Nomenclature. Last updated Oct. 18, 2010.
Available @ https://planetarynames.wr.usgs.gov/Feature/3683

Jones, Eric M. “Landing at Descartes.” NASA > Apollo 16 Lunar Surface Journal. 1995. Last revised Dec. 9, 2015.
Available @ https://www.hq.nasa.gov/alsj/a16/a16.html

King, Bob. “How to See All Six Apollo Moon Landing Sites.” Sky & Telescope > Observing. April 22, 2015.
Available @ https://www.skyandtelescope.com/observing/how-to-see-all-six-apollo-moon-landing-sites/

King, Bob. “How to See Lunar Craters With the Naked Eye.” Sky & Telescope > Observing. Oct. 28, 2015.
Available @ https://www.skyandtelescope.com/observing/how-to-see-lunar-craters-with-the-naked-eye102820152810/

King, Bob. Night Sky With the Naked Eye. Salem MA: Page Street Publishing Co., 2016.

Levy, David H. Skywatching. Revised and updated. San Francisco CA: Fog City Press, 1994.

Lunar Planetary Institute. “Apollo 16 Mission: Landing Site Overview.” USRA (Universities Space Research Association) Lunar Planetary Institute (LPI) > The Moon > Lunar Mission Summaries > Apollo Missions.
Available @ https://www.lpi.usra.edu/lunar/missions/apollo/apollo_16/landing_site/

Marriner, Derdriu. “First October 2020 Full Moon Shows Apollo 11’s Mare Tranquillitatis.” Earth and Space News. Wednesday, Sept. 30, 2020.
Available @ https://earth-and-space-news.blogspot.com/2020/09/first-october-2020-full-moon-shows.html

Marriner, Derdriu. “Six Lunar Maria Shape the Man in the Moon for Northern Hemisphere Viewers.” Earth and Space News. Wednesday, May 3, 2017.
Available @ https://earth-and-space-news.blogspot.com/2017/05/six-lunar-maria-shape-man-in-moon-for.html

Marriner, Derdriu. “Last Quarter Saturday, Oct. 10, Shows Apollo 12’s Oceanus Procellarum.” Earth and Space News. Wednesday, Oct. 7, 2020.
Available @ https://earth-and-space-news.blogspot.com/2020/10/last-quarter-saturday-oct-10-shows.html

Marriner, Derdriu. “Waxing Crescent Wednesday, Oct. 21, Shows Apollo 17’s Mare Serenitatis.” Earth and Space News. Wednesday, Oct. 14, 2020.
Available @ https://earth-and-space-news.blogspot.com/2020/10/waxing-crescent-wednesday-oct-21-shows.html

Masursky, Harold; G.W. Colton; and Farouk El-Baz. “Chapter 2: Regional Views.” Apollo Over the Moon: A View From the Orbit: 30-43. NASA SP-362. Washington DC: National Aeronautics and Space Administration Scientific and Technical Information Office, 1978.
Available @ https://history.nasa.gov/SP-362/contents.htm

Neal-Jones, Nancy. “LRO Briefing: Latest Images of Apollo Landing Sites.” NASA > Missions > LRO (Lunar Reconnaissance Orbiter) > News. Sept. 6, 2011.
Available @ https://www.nasa.gov/mission_pages/LRO/news/lro-briefing-20110906.html

Neal-Jones, Nancy; Elizabeth Zubritsky; and Steve Cole. “NASA Spacecraft Images Offer Sharper Views of Apollo Landing Sites.” NASA > Missions > LRO (Lunar Reconnaissance Orbiter) > News. Sept. 5, 2011. Last updated Aug. 7, 2017.
Available @ https://www.nasa.gov/mission_pages/LRO/news/apollo-sites.html

Ridpath, Ian; and Wil Tirion. Stars & Planets: The Complete Guide to the Stars, Constellations, and the Solar System. Updated and expanded edition. Princeton NJ; Oxford UK: Princeton University Press, 2017.

Simmons, Gene. On the Moon With Apollo 16: A Guidebook to the Descartes Region. NASA EP-95. Washington DC: National Aeronautics and Space Administration, April 1972.
Available via NASA NTRS (NASA Technical Reports Server) @ https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19720012229.pdf

Smithsonian National Air and Space Museum. “Apollo 16: Facts.” Smithsonian National Air and Space Museum > Missions > Apollo 12.
Available @ https://airandspace.si.edu/explore-and-learn/topics/apollo/apollo-program/landing-missions/apollo16-facts.cfm

Stratton, F.J.M. (Frederick John Marrian), ed. Vth General Assembly Transactions of the IAU Vol. V Proceedings of the 5th General Assembly Paris, France, July 10-17, 1935. Cambridge University Press, Jan. 1, 1936.
Available @ https://www.iau.org/publications/iau/transactions_b/

Time and Date. “The First Quarter / Half Moon.” Time and Date > Sun & Moon > Moon.
Available @ https://www.timeanddate.com/astronomy/moon/first-quarter.html

Time and Date. “The Phases of the Moon.” Time and Date > Sun & Moon > Moon.
Available @ https://www.timeanddate.com/calendar/aboutmoonphases.html

Ulrich, George E.; Carroll Ann Hodges; and William R. Muehlberger, eds. Geology of the Apollo 16 Area, Central Lunar Highlands. Prepared on behalf of the National Aeronautics and Space Administration. Geological Survey Professional Paper 1048. Washington DC: U.S. Government Printing Office, 1981.
Available @ http://an.rsl.wustl.edu/apollo/data/A16/resources/USGS_1048.pdf

U.S. Geological Survey. Color-Coded Topography and Shaded Relief Map of the Lunar Near Side and Far Side Hemispheres. U.S. Geological Survey Geologic Investigations Series I-2769. Page last modified Nov. 30, 2016. Flagstaff AZ: U.S. Geological Survey Astrogeology Science Center, 2003.
Available @ https://pubs.usgs.gov/imap/i2769/

U.S.N.O. Astronomical Applications Department. “Fraction of the Moon Illuminated, 2020 at Midnight.” U.S. Naval Observatory Astronomical Applications Department > Astronomical Information Center > Phenomena of the Sun and Moon > Phases of the Moon and Percent of the Moon Illuminated.
Available @ https://aa.usno.navy.mil/cgi-bin/aa_moonill2.pl?form=1&year=2020

U.S.N.O. Astronomical Applications Department. “Phases of the Moon and Percent of the Moon Illuminated.” U.S. Naval Observatory Astronomical Applications Department > Astronomical Information Center > Phenomena of the Sun and Moon.
Available @ https://aa.usno.navy.mil/faq/docs/moon_phases.php

Whitaker, Ewen A. (Adair). Mapping and Naming the Moon: A History of Lunar Cartography and Nomenclature. Cambridge UK; New York NY: Cambridge University Press, 1999.

Williams, David R.; and E. (Edwin) Bell II, cur. “Apollo Landing Site Coordinates.” NASA Goddard Space Flight Center > Solar System Exploration > The Moon > Lunar Exploration > Precise Positions of LM’s and Science Experiments on the Moon. Last updated March 6, 2017.
Available @ https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=1972-096C

Wood, Charles A. “Rings and Things.” Sky & Telescope > Observing. Aug. 1, 2006.
Available @ https://www.skyandtelescope.com/observing/celestial-objects-to-watch/rings-and-things/