Sayh al Uhaymir 169
Sayh al Uhaymir 169 or SaU 169 for short is a lunar meteorite that was discovered on January 16, 2002 by Bern scientists working with Edwin Gnos in the desert of Oman and then researched. It was named after its place of discovery and is the first meteorite for which the exact place of origin on its mother body could be determined.
The meteorite is 70 × 43 × 40 mm in size and weighs 208 grams. Inside it is greenish gray with a dark surface and various regolitic inclusions . The composition of the meteorite was determined using geochemical investigations. SaU 169 is unusually rich in the elements uranium and thorium and is therefore the most radioactive of all known meteorites.
Due to the regional distribution of various elements on the moon, as measured by the lunar probes Clementine and Lunar Prospector , as well as the temporal division and comparisons with the lunar surface, its origin could be determined exactly. It comes from the area of the Lalande crater , probably from a 3 km large crater 70 km north-northeast of Lalande.
SaU 169 originated 3.9 billion ± 13 million years ago in the Mare Imbrium region on the Earth's moon and was later hit by three other impacts 2.8 billion, 200 million and 340,000 years ago. On the last impact, it was thrown into space and captured by the Earth's gravity. It fell to earth around 10,000 years ago in what is now Oman.
SaU 169 is of particular scientific importance as it enables a more precise chronological dating of the Mare Imbrium.
literature
- Edwin Gnos, Beda A. Hofmann, Ali Al-Kathiri, Silvio Lorenzetti, Otto Eugster, Martin J. Whitehouse, Igor M. Villa, AJ Timothy Jull, Jost Eikenberg, Bernhard Spettel, Urs Krähenbühl, Ian A. Franchi, Richard C. Greenwood: Pinpointing the Source of a Lunar Meteorite: Implications for the Evolution of the Moon . In: Science . Vol. 305, No. 5684 , 2004, p. 657-659 , doi : 10.1126 / science.1099397 .