Flag (crater)

Flag crater is a small crater in the Descartes Highlands of the Moon visited by the astronauts of Apollo 16. The name of the crater was formally adopted by the IAU in 1973.[1] Geology Station 1 is adjacent to Flag, at the much smaller Plum crater.

Flag
Apollo 16 image, with Flag left of center and Spook right of center. Plum is the tiny crater on the southeast rim of Flag.
Coordinates8.97°S 15.45°E / -8.97; 15.45
Diameter240 m[1]
EponymAstronaut-named feature

On April 21, 1972, the Apollo 16 Apollo Lunar Module (LM) Orion landed about 1.5 km east of Flag, which is between the prominent North Ray and South Ray craters. The astronauts John Young and Charles Duke explored the area over the course of three EVAs using a Lunar Roving Vehicle, or rover. They drove to Flag on EVA 1.

Panorama of Flag crater taken by Charlie Duke, facing northwest at center
Panorama of Plum crater, to the left of the panorama above, facing southwest. Mission Commander John Young at left. The astronauts sampled soil in the foreground, and a boulder on the distal crater rim. Sample 61016, called Big Muley, is just above the right end of Young's shadow.
Planimetric map of Station 1 from the Apollo 16 Preliminary Science Report. X indicates sample locations, 5-digit numbers are LRL sample numbers, rectangle is lunar rover (dot indicates TV camera), black spots are large rocks, dashed lines are crater rims or other topographic features, and triangles are panorama stations.
TV camera still of Duke (left) and Young on the rim of Plum. Duke remarked at this time, "John, you are just beautiful. That is the most beautiful sight." Young is standing next to a boulder from which sample 61295 was taken.
Young took this photo of Duke with Plum and the rover in the background from where he is standing in the above TV still.

Flag crater is approximately 240 m in diameter and over 20 m deep.[2] The adjacent crater Plum is only about 30 m in diameter.[3] The slightly larger crater Spook, also visited by the astronauts, lies less than 1 km to the east.

Flag cuts into the Cayley Formation of Imbrian age.[4]

Samples

The following samples were collected from the vicinity of Plum and Flag crater (Station 1), as listed in Table 6-II of the Apollo 16 Preliminary Science Report,[5] which does not include samples smaller than 25 g weight (of which there were many). Sample type, lithology, and descriptions are from the Lunar Sample Atlas of the Lunar and Planetary Institute.[6]

SampleSample TypeLithologyPhotoDescription
61015rockbrecciacoated with black glass on one side and is thought to be ejecta from

South Ray crater

61016rockimpact melt brecciaknown as Big Muley; named after Bill Muehlberger,

the leader of the Apollo 16 field geology team

61135rockregolith brecciaan ancient regolith breccia that became a closed system

about 3.9 b.y. ago; and has a few zap pits

61155rakebrecciaclast-rich "glassy impact melt"; has abundant white clasts,

thin glass veins and glassy mesostasis

61156rockimpact melt brecciaTough, medium gray, poikilitic impact melt

that has been thermally metamorphosed

61175rockfragmental brecciaContains a high percentage of glass, with some agglutinate.

It also contains a small, but significant, mare component

61195rockbrecciacoherent, medium grey breccia with a glassy matrix and abundant clasts;

zap pits are surrounded with wide spall zones

61295rockbrecciafriable light matrix breccia with both light and dark clasts;

rounded and has many zap pits

61536rakebrecciacontains a large white clast held within a glass matrix,

and has a thin glass coating on surface

61546rakebrecciavesicular chunk of glass with numerous small white clasts

and micrometeorite craters on one side only

References
  1. Flag, Gazetteer of Planetary Nomenclature, International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN)
  2. Apollo 16 Landing Area, 78D2S1(50), NASA Lunar Topophotomap. Published by The Defense Mapping Agency, November 1974. Available from Lunar and Planetary Institute.
  3. Plum, Gazetteer of Planetary Nomenclature, International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN)
  4. Geologic Map of the Apollo 16 (Descartes) Landing Area by Apollo Field Geology Investigation Team (D. P. Elston, E. L. Boudette, J. P. Schafer), United States Geological Survey, April 1972
  5. Apollo 16 Preliminary Science Report (NASA SP-315), 1972
  6. Lunar Sample Atlas, Lunar and Planetary Institute
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