Sayh al Uhaymir 169
Encyclopedia
Sayh al Uhaymir 169 is a 206g lunar meteorite
found in the Sayh al Uhaymir region of the Sultanate of Oman
in January 2002.
This stone is an impact-melt
breccia
with exceedingly high concentrations of thorium
and other incompatible elements; phosphorus
, rare earth element
s, and the three most important naturally occurring radioactive elements, potassium
, thorium
, and uranium
have been segregated in the liquid phase when the lunar mineral
s crystallized. The impact that eventually sent this stone to the Earth is dated at 3.9 million years and could be the Imbrium impact
. It collided with the Earth 9.7 ± 1.3 kya.
It is complete, a light gray-greenish rounded stone, dimensions 70x43x40mm and mass 206 grams, found on January 16, 2002, in the central desert of Oman at 20° 34.391'N and 57° 19.400' E.
According to geologist Edwin Gnos and coworkers, the meteorite's origin can be pinpointed to the vicinity of the Lalande impact crater
; isotopic analysis shows a complex history of four distinct lunar impacts:
"Crystallization of the impact melt occurred at 3909 ± 13 Ma, followed by exhumation by a second impact at 2800 Ma, which raised the sample to a regolith position at unconstrained depth. A third impact at 200 Ma moved the material closer to the lunar surface, where it mixed with solar-wind–containing regolith. It was launched into space by a fourth impact at <0.34 Ma" (Science
2004, vol 305, pp657–9, July 2004).
Lunar meteorite
A Lunar meteorite is a meteorite that is known to have originated on the Moon.-Discovery:In January 1982, John Schutt, leading an expedition in Antarctica for the ANSMET program, found a meteorite that he recognized to be unusual...
found in the Sayh al Uhaymir region of the Sultanate of Oman
Oman
Oman , officially called the Sultanate of Oman , is an Arab state in southwest Asia on the southeast coast of the Arabian Peninsula. It is bordered by the United Arab Emirates to the northwest, Saudi Arabia to the west, and Yemen to the southwest. The coast is formed by the Arabian Sea on the...
in January 2002.
This stone is an impact-melt
Impact event
An impact event is the collision of a large meteorite, asteroid, comet, or other celestial object with the Earth or another planet. Throughout recorded history, hundreds of minor impact events have been reported, with some occurrences causing deaths, injuries, property damage or other significant...
breccia
Breccia
Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....
with exceedingly high concentrations of thorium
Thorium
Thorium is a natural radioactive chemical element with the symbol Th and atomic number 90. It was discovered in 1828 and named after Thor, the Norse god of thunder....
and other incompatible elements; phosphorus
Phosphorus
Phosphorus is the chemical element that has the symbol P and atomic number 15. A multivalent nonmetal of the nitrogen group, phosphorus as a mineral is almost always present in its maximally oxidized state, as inorganic phosphate rocks...
, rare earth element
Rare earth element
As defined by IUPAC, rare earth elements or rare earth metals are a set of seventeen chemical elements in the periodic table, specifically the fifteen lanthanides plus scandium and yttrium...
s, and the three most important naturally occurring radioactive elements, potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
, thorium
Thorium
Thorium is a natural radioactive chemical element with the symbol Th and atomic number 90. It was discovered in 1828 and named after Thor, the Norse god of thunder....
, and uranium
Uranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
have been segregated in the liquid phase when the lunar mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...
s crystallized. The impact that eventually sent this stone to the Earth is dated at 3.9 million years and could be the Imbrium impact
Mare Imbrium
Mare Imbrium, Latin for "Sea of Showers" or "Sea of Rains", is a vast lunar mare filling a basin on Earth's Moon and one of the larger craters in the Solar System. Mare Imbrium was created when lava flooded the giant crater formed when a very large object hit the Moon long ago...
. It collided with the Earth 9.7 ± 1.3 kya.
It is complete, a light gray-greenish rounded stone, dimensions 70x43x40mm and mass 206 grams, found on January 16, 2002, in the central desert of Oman at 20° 34.391'N and 57° 19.400' E.
According to geologist Edwin Gnos and coworkers, the meteorite's origin can be pinpointed to the vicinity of the Lalande impact crater
Lalande (crater)
Lalande is a small lunar impact crater that lies in the central part of the visible Moon, on the eastern edge of Mare Insularum. The crater is surrounded by a high-albedo area of ejecta that extends into a ray system with a maximum radius of over 300 kilometers. The interior wall has a terrace...
; isotopic analysis shows a complex history of four distinct lunar impacts:
"Crystallization of the impact melt occurred at 3909 ± 13 Ma, followed by exhumation by a second impact at 2800 Ma, which raised the sample to a regolith position at unconstrained depth. A third impact at 200 Ma moved the material closer to the lunar surface, where it mixed with solar-wind–containing regolith. It was launched into space by a fourth impact at <0.34 Ma" (Science
Science (journal)
Science is the academic journal of the American Association for the Advancement of Science and is one of the world's top scientific journals....
2004, vol 305, pp657–9, July 2004).
External links
- http://epsc.wustl.edu/admin/resources/meteorites/sau169.html
- http://illite.unibe.ch/sau169/
- http://www.ilexikon.com/Sayh_al_Uhaymir_169.html
- http://www.zeit.de/2004/33/3_Fragen