Lunar Sample 15016, better known as the "Seatbelt Basalt", 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 as ...
discovered and collected on the
Apollo 15
Apollo 15 (July 26August 7, 1971) was the ninth crewed mission in the United States' Apollo program and the fourth to Moon landing, land on the Moon. It was the first List of Apollo missions#Alphabetical mission types, J mission, with a ...
mission in 1971 in the
Hadley-Apennine region of the Moon. The rock is a vesicular
olivine
The mineral olivine () is a magnesium iron silicate with the chemical formula . It is a type of nesosilicate or orthosilicate. The primary component of the Earth's upper mantle, it is a common mineral in Earth's subsurface, but weathers quickl ...
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 so named because mission commander,
David Scott
David Randolph Scott (born June 6, 1932) is an American retired test pilot and NASA astronaut who was the seventh person to walk on the Moon. Selected as part of the third group of astronauts in 1963, Scott flew to space three times and c ...
, noticed it on the surface while driving the
Lunar Roving Vehicle
The Lunar Roving Vehicle (LRV) is a battery-powered four-wheeled rover used on the Moon in the last three missions of the American Apollo program ( 15, 16, and 17) during 1971 and 1972. It is popularly called the Moon buggy, a play on the t ...
and stopped to collect it, but said to mission control that he was just fastening his seatbelt. He did this because he assumed mission control would not give permission to stop for a sample collection due to time constraints. This unplanned stop was later designated Geology Station 3, located about west of
Rhysling crater.
This sample was collected from an area with abundant subdued craters between in diameter. The sample is a very vesicular basalt, rounded by surface erosion. Lithologically, it closely resembles samples 15535 and 15536, as well as a number of fragments in the rake samples from station 9A.
The seatbelt basalt 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 ...
at the
Lyndon B. Johnson Space Center
The Lyndon B. Johnson Space Center (JSC) is NASA's center for human spaceflight (originally named the Manned Spacecraft Center), where human spaceflight training, research, and flight control are conducted. It was renamed in honor of the late U ...
. A piece of it is on display at the
National Air and Space Museum
The National Air and Space Museum of the Smithsonian Institution, also called the Air and Space Museum, is a museum in Washington, D.C., in the United States.
Established in 1946 as the National Air Museum, it opened its main building on the Nat ...
in Washington, DC.
Description
The seatbelt basalt is a highly-
vesicular,
olivine
The mineral olivine () is a magnesium iron silicate with the chemical formula . It is a type of nesosilicate or orthosilicate. The primary component of the Earth's upper mantle, it is a common mineral in Earth's subsurface, but weathers quickl ...
-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 ...
with
phenocryst
300px, feldspathic phenocrysts. This granite, from the Switzerland">Swiss side of the Mont Blanc massif, has large white plagioclase phenocrysts, triclinic minerals that give trapezoid shapes when cut through). 1 euro coins, 1 euro coin (diameter ...
s of zoned
pyroxene
The pyroxenes (commonly abbreviated to ''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 calcium (Ca), sodium (Na), iron (Fe II) ...
and olivine within a matrix of pyroxene and
plagioclase
Plagioclase is a series of tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more prope ...
. The rock also contains
ilmenite
Ilmenite is a titanium-iron oxide mineral with the idealized formula . It is a weakly magnetic black or steel-gray solid. Ilmenite is the most important ore of titanium and the main source of titanium dioxide, which is used in paints, printing ...
and
ulvöspinel
Ulvöspinel or ulvite is an iron titanium oxide mineral with formula: iron, Fe2titanium, Tioxygen, O4 or TiFe2+2O4. It forms brown to black metallic Cubic (crystal system), isometric crystals with a Mohs hardness of 5.5 to 6. It belongs to the sp ...
.
Age
The rock's
cosmic ray
Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own ...
exposure age was discovered to be about 285 million years. Another study determined the age to be 315 million years.
The rock's age of formation has been estimated to be approximately 3.29 ± 0.05 billion years from
Rb-
Sr radiometric dating
Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares t ...
.
[Evensen, N. M., Murthy, V. R. and Coscio, M. R. (1973) Rb-Sr ages of some mare basalts and the isotopic and trace element systematics in lunar fines. ''Proc. 4th Lunar Sci. Conf.'' 1707-1724.]
References
External links
Sample 15016
{{Apollo program, state=collapsed
Apollo 15
Lunar science
Lunar samples
David Scott
Basalt
Imbrian