Lunar Sample 15555, better known as "Great Scott", is a

lunar sample 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 a ...

discovered and collected on the

Apollo 15 Apollo 15 (July 26August 7, 1971) was the ninth crewed mission in the Apollo program and the fourth Moon landing. It was the first List of Apollo missions#Alphabetical mission types, J mission, with a longer stay on the Moon and a greate ...

mission in 1971 in the Hadley-Apennine region of the Moon. The rock is a

olivine The mineral olivine () is a magnesium iron Silicate minerals, silicate with the chemical formula . It is a type of Nesosilicates, nesosilicate or orthosilicate. The primary component of the Earth's upper mantle (Earth), upper mantle, it is a com ...

-normative

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

. It is named after mission commander

David Scott David Randolph Scott (born June 6, 1932) is an American retired test pilot and NASA astronaut who was the List of Apollo astronauts#People who have walked on the Moon, seventh person to walk on the Moon. Selected as part of the NASA Astronaut ...

, and it is the largest sample returned to Earth from the mission, as well as the most intensively studied. It was collected by Scott on the rim of Hadley Rille, at station 9A. Great Scott is currently stored at the

Lunar Sample Laboratory Facility The Lunar Sample Laboratory Facility (LSLF) is a repository and laboratory facility at NASA's Lyndon B. Johnson Space Center in Houston, Texas, opened in 1979 to house geologic samples returned from the Moon by the Apollo program missions to th ...

at the Lyndon B. Johnson Space Center. Pieces of it are on display at the

National Museum of Natural History The National Museum of Natural History (NMNH) is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. With 4.4 ...

in Washington, DC, the

Tellus Science Museum Tellus Science Museum is a natural history and science museum near Cartersville, Georgia, United States, with a facility of over 120,000 square feet. It is an affiliate of the Smithsonian Institution. The museum holds multiple special events throug ...

in the state of Georgia, the

Madrid Deep Space Communications Complex The Madrid Deep Space Communications Complex (MDSCC; in Spanish and officially ''Complejo de Comunicaciones de Espacio Profundo de Madrid'') is a satellite ground station located in Robledo de Chavela, Spain, and operated by the Instituto Nac ...

in Spain, the LROC Lunar Exploration Museum at

Arizona State University Arizona State University (Arizona State or ASU) is a public university, public research university in Tempe, Arizona, United States. Founded in 1885 as Territorial Normal School by the 13th Arizona Territorial Legislature, the university is o ...

and the

Science Museum A science museum is a museum devoted primarily to science. Older science museums tended to concentrate on static displays of objects related to natural history, paleontology, geology, Industry (manufacturing), industry and Outline of industrial ...

in London, England. The term ''Great Scott'' was in use as soon as the next mission,

Apollo 16 Apollo 16 (April 1627, 1972) was the tenth human spaceflight, crewed mission in the United States Apollo program, Apollo space program, administered by NASA, and the fifth and penultimate to Moon landing, land on the Moon. It was the second o ...

, because Charlie Duke used the term just before picking up

Big Muley 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 (Station 1). It is the largest sample returned fr ...

. Big Muley is the largest sample (11.7 kg) returned from the Moon, and Great Scott is the second largest.

Description

Lunar sample 15555 is a coarse-grained,

porphyritic Porphyritic is an adjective used in geology to describe igneous rocks with a distinct difference in the size of mineral crystals, with the larger crystals known as phenocrysts. Both extrusive and intrusive rocks can be porphyritic, meaning ...

rock with rounded

phenocryst image:montblanc granite phenocrysts.JPG, 300px, Granites often have large feldspar, feldspathic phenocrysts. This granite, from the Switzerland, Swiss side of the Mont Blanc massif, has large white phenocrysts of plagioclase (that have trapezoid sh ...

s (1 mm) and subhedral zoned

pyroxene The pyroxenes (commonly abbreviated Px) are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula , where X represents ions of calcium (Ca), sodium (Na), iron ( ...

phenocrysts (0.5–2 mm) set in a matrix of

poikilitic Poikilitic texture refers to igneous rocks where large later-formed less perfect crystals ('oikocrysts') surround smaller early-formed idiomorphic crystals ('chadacrysts') of other minerals. A poikilitic texture is most easily observed in petrog ...

plagioclase Plagioclase ( ) is a series of Silicate minerals#Tectosilicates, tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continu ...

(up to 3 mm).Lunar Sample 15555
Lunar Sample Atlas, Lunar and Planetary Institute File:Lunar sample 15555 S71-43393.jpg, Great Scott in the Lunar Sample Laboratory Facility. The dark spot surrounded by a light halo in the center of the sample is a

Micrometeoroid A micrometeoroid is a tiny meteoroid: a small particle of rock in space, usually weighing less than a gram. A micrometeorite is such a particle that survives passage through Earth's atmosphere and reaches Earth's surface. The term "micrometeoro ...

impact, or "zap pit." File:Lunar Olivine Basalt 15555 from Apollo 15 in National Museum of Natural History.jpg, Cut fragment on display at the

File:Lunar sample 15555, Tellus Museum (09).jpg, Fragment on display at the

, Cartersville, Georgia File:Great scott moon rock science museum.JPG, Fragment on display at the

Science Museum, London The Science Museum is a major museum on Exhibition Road in South Kensington, London. It was founded in 1857 and is one of the city's major tourist attractions, attracting 3.3 million visitors annually in 2019. Like other publicly funded ...

References

{{Apollo program, state=collapsed Lunar samples Apollo 15 David Scott Basalt

Description

See also

References