Descartes Highlands

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Aerial photo of the Descartes Highlands with features and Apollo 16 mission traverses labeled. Apollo 16 landingsite.jpg
Aerial photo of the Descartes Highlands with features and Apollo 16 mission traverses labeled.

The Descartes Highlands is an area of lunar highlands located on the near side that served as the landing site of the American Apollo 16 mission in early 1972. The Descartes Highlands is located in the area surrounding Descartes crater, after which the feature received its name. [1]

Contents

Geology

Two major formations dominate the Descartes Highlands area: the Cayley Formation and the Descartes Formation. The latter is composed primarily of highland plateau material, perhaps debris from large impact events—specifically the impact that formed Mare Nectaris. [2] North Ray and South Ray craters, the former sampled directly by the Apollo 16 crew, revealed a layering sequence, possibly an overlap of the Cayley and Descartes formations. [1]

The area of the Descartes Highlands is characterized by an undulating landscape covered with old and some new, sharp rimmed craters. Based upon findings during the Apollo 16 mission, some of the floors of these craters were covered with glass similar to that found at the Taurus-Littrow landing site on Apollo 17. According to Apollo 16 commander John Young, the arrangement of the glass gave it the appearance of dried mud. [3]

Before Apollo 16 sampled the Descartes Highlands, it was believed that volcanic material would be abundant in the area after visual analysis of the features there. It was thought that the formations in the area were formed by lavas more viscous than the lavas that formed the Lunar mare. This was later disproved after the analysis of samples from the area. It was revealed that many of the rocks in the area are not volcanic in origin, but breccias composed of fragments from several lunar impacts. [4] Astronauts Young and Duke visited Sudbury, Ontario, Canada in July 1971 to examine shatter cones. Sudbury is a site of a large meteor impact exhibiting substantial evidence of shatter cone geology. In the Descartes Highlands, it was determined that the region's topography was formed by meteor impact instead of volcanic activity.

Landing site selection

All of the preceding Apollo landing missions sampled Lunar mare material, either directly or indirectly. A landing site in the Lunar highlands was to be selected with the goal of investigating the material located there. Two landing sites were given consideration to achieve this goal: the Descartes site and the crater Alphonsus. [3]

The Descartes Highlands was selected for the Apollo 16 mission in order to enable astronauts John Young and Charles Duke to sample the prominent Descartes and Cayley formations concentrated in the area. Sampling these formations was a priority, as the two cover much of the near side of the Moon. Priority was also given to locating and obtaining samples of old highland material that was older than the Imbrium impact in order to give insight to the geologic timeline and composition of the Moon. North Ray and South Ray craters, both prominent features in the immediate landing area, were also prioritized because material from the prominent formations in the area had been naturally excavated there by the impacts that formed them. [3]

See also

Related Research Articles

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<span class="mw-page-title-main">Oceanus Procellarum</span> Vast lunar mare on the western edge of the near side of Earths Moon

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<span class="mw-page-title-main">Mare Marginis</span> Lunar mare

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<span class="mw-page-title-main">Mare Nectaris</span> Feature on the moon

Mare Nectaris is a small lunar mare or sea located south of Mare Tranquillitatis southwest of Mare Fecunditatis, on the near side of the Moon. Montes Pyrenaeus borders the mare to the east and Sinus Asperitatis fuses to its northwestern edge. It is 84,000 square kilometers in size.

<span class="mw-page-title-main">Fra Mauro formation</span> Location on the Moon; landing site for the Apollo 14 mission

The Fra Mauro formation is a formation on the near side of Earth's Moon that served as the landing site for the American Apollo 14 mission in 1971. It is named after the 80-kilometer-diameter crater Fra Mauro, located within it. The formation, as well as Fra Mauro crater, take their names from a 15th-century Italian monk and mapmaker of the same name. Apollo 13 was originally scheduled to land in the Fra Mauro highlands, but was unable due to an in-flight technical failure.

<span class="mw-page-title-main">Lunar geologic timescale</span> Geological dating system of the Moon

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<span class="mw-page-title-main">Alphonsus (crater)</span> Crater on the Moon

Alphonsus is an ancient impact crater on the Moon that dates from the pre-Nectarian era. It is located on the lunar highlands on the eastern end of Mare Nubium, west of the Imbrian Highlands, and slightly overlaps the crater Ptolemaeus to the north. To the southwest is the smaller Alpetragius. The crater name was approved by the IAU in 1935.

<span class="mw-page-title-main">Far side of the Moon</span> Hemisphere of the Moon that always faces away from Earth

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<span class="mw-page-title-main">Geology of the Moon</span> Structure and composition of the Moon

The geology of the Moon is quite different from that of Earth. The Moon lacks a true atmosphere, and the absence of free oxygen and water eliminates erosion due to weather. Instead, the surface is eroded much more slowly through the bombardment of the lunar surface by micrometeorites. It does not have any known form of plate tectonics, it has a lower gravity, and because of its small size, it cooled faster. In addition to impacts, the geomorphology of the lunar surface has been shaped by volcanism, which is now thought to have ended less than 50 million years ago. The Moon is a differentiated body, with a crust, mantle, and core.

<span class="mw-page-title-main">Moon rock</span> Rocks on or from the Moon

Moon rock or lunar rock is rock originating from Earth's Moon. This includes lunar material collected during the course of human exploration of the Moon, and rock that has been ejected naturally from the Moon's surface and landed on Earth as meteorites.

<span class="mw-page-title-main">Cayley Formation</span>

The Cayley Formation is a discontinuous unit of plains-forming material on the Moon. It was first recognized in the central near side of the Moon in 1965, by the Astrogeology group of the United States Geological Survey. It was previously mapped as part of the Fra Mauro formation. During the Apollo era, the formation was mapped in many other parts of the Moon including the far side

<span class="mw-page-title-main">Taurus–Littrow</span> Lunar valley

Taurus–Littrow is a lunar valley located on the near side at the coordinates 20.0°N 31.0°E. It served as the landing site for the American Apollo 17 mission in December 1972, the last crewed mission to the Moon. The valley is located on the southeastern edge of Mare Serenitatis along a ring of mountains formed between 3.8 and 3.9 billion years ago when a large object impacted the Moon, forming the Serenitatis basin and pushing rock outward and upward.

<span class="mw-page-title-main">Hadley–Apennine</span> Moon landing site of American Apollo 15

Hadley–Apennine is a region on the near side of Earth's Moon that served as the landing site for the American Apollo 15 mission, the fourth crewed landing on the Moon and the first of the "J-missions", in July 1971. The site is located on the eastern edge of Mare Imbrium on a lava plain known as Palus Putredinis. Hadley–Apennine is bordered by the Montes Apenninus, a mountain range, and Hadley Rille, a meandering channel, on the east and west, respectively.

<span class="mw-page-title-main">Big Muley</span> Largest lunar rock collected during the Apollo program

Lunar Sample 61016, better known as "Big Muley", is a lunar sample discovered and collected on the Apollo 16 mission in 1972 in the Descartes Highlands, on the rim of Plum crater, near Flag crater. It is the largest sample returned from the Moon as part of the Apollo program. The rock, an 11.7 kg (26 lb) breccia consisting mainly of shocked anorthosite attached to a fragment of troctolitic "melt rock", is named after Bill Muehlberger, the Apollo 16 field geology team leader.

<span class="mw-page-title-main">North Ray (crater)</span> Crater on the Moon

North Ray 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. It is the largest crater sampled by astronauts during the Apollo program.

<span class="mw-page-title-main">South Ray (crater)</span> Crater on the Moon

South Ray crater is a small crater in the Descartes Highlands of the Moon photographed from the lunar surface by the astronauts of Apollo 16. The name of the crater was formally adopted by the IAU in 1973.

<span class="mw-page-title-main">Palmetto (crater)</span> Crater on the Moon

Palmetto 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.

<span class="mw-page-title-main">Flag (crater)</span> Lunar crater explored on Apollo 16

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. Geology Station 1 is adjacent to Flag, at the much smaller Plum crater.

<span class="mw-page-title-main">Spook (crater)</span> Lunar crater explored on Apollo 16

Spook 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. Geology Station 2 is adjacent to Spook, between it and the smaller, younger crater called Buster to the north of it.

References

  1. 1 2 "Apollo 16 Landing Site". The Apollo Program. National Air and Space Museum. Retrieved 12 September 2010.
  2. Bussey, D. Ben J.; Spudis, Paul D. (25 February 2000). "Compositional Studies of the Orientale, Humorum, Nectaris, and Crisium Lunar Basins" (PDF). Journal of Geophysical Research. 105 (E2): 4241. Bibcode:2000JGR...105.4235B. doi: 10.1029/1999je001130 . Retrieved 16 August 2018.
  3. 1 2 3 "Apollo 16 Mission Landing Site Overview". Apollo 16 Mission. Lunar and Planetary Institute. Retrieved 12 September 2010.
  4. Taylor; Gorton; Muir; Nance; Rudowski; Ware (December 1973). "Composition of the Descartes region, lunar highlands". Geochimica et Cosmochimica Acta. 37 (12): 2665–2683. Bibcode:1973GeCoA..37.2665T. doi:10.1016/0016-7037(73)90271-8.