Lalande (crater)
Encyclopedia
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 system, and there is a small central rise at the mid-point of the floor. This crater is believed to have formed about 2.8 billion years ago.
In 2002, a meteorite was discovered in the Oman
desert by Edwin Gnos of the University of Berne
. This rock, identified as Sayh al Uhaymir 169
, is believed to have originated from the Moon. It was ejected from the surface during an impact that occurred less than 340,000 years in the past. Scientists now think that the rock originated from the crater ejecta blanket surrounding Lalande.
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
impact crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
that lies in the central part of the visible Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
, on the eastern edge of Mare Insularum
Mare Insularum
Mare Insularum is a lunar mare located in the Insularum basin just south of Mare Imbrium. The basin material is of the Lower Imbrian epoch, with the mare material of the Upper Imbrian epoch. The mare is bordered by the craters Copernicus on the east, and Kepler on the west...
. The crater is surrounded by a high-albedo
Albedo
Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...
area of ejecta that extends into a ray system
Ray system
A ray system comprises radial streaks of fine ejecta thrown out during the formation of an impact crater, looking a bit like many thin spokes coming from the hub of a wheel. The rays can extend for lengths up to several times the diameter of their originating crater, and are often accompanied by...
with a maximum radius of over 300 kilometers. The interior wall has a terrace system, and there is a small central rise at the mid-point of the floor. This crater is believed to have formed about 2.8 billion years ago.
In 2002, a meteorite was discovered in the 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...
desert by Edwin Gnos of the University of Berne
University of Berne
The University of Bern is a university in the Swiss capital of Bern and was founded in 1834. It is regulated and financed by the Canton of Bern. It is a comprehensive university offering a broad choice of courses and programmes in eight faculties and some 160 institutes. The university is an...
. This rock, identified as Sayh al Uhaymir 169
Sayh al Uhaymir 169
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 elements, and the three most...
, is believed to have originated from the Moon. It was ejected from the surface during an impact that occurred less than 340,000 years in the past. Scientists now think that the rock originated from the crater ejecta blanket surrounding Lalande.
Satellite craters
By convention these features are identified on lunar maps by placing the letter on the side of the crater mid-point that is closest to Lalande.| Lalande | Latitude | Longitude | Diameter |
|---|---|---|---|
| A | 6.6° S | 9.8° W | 13 km |
| B | 3.1° S | 9.0° W | 8 km |
| C | 5.6° S | 6.9° W | 11 km |
| D | 6.1° S | 7.5° W | 8 km |
| E | 3.4° S | 10.7° W | 4 km |
| F | 2.6° S | 10.0° W | 3 km |
| G | 6.2° S | 7.9° W | 5 km |
| N | 5.6° S | 5.7° W | 6 km |
| R | 4.7° S | 7.0° W | 24 km |
| T | 5.2° S | 7.5° W | 4 km |
| U | 3.2° S | 8.1° W | 4 km |
| W | 6.5° S | 5.6° W | 11 km |
External links
- Rock traced from moon crater to Earth — CNNCNNCable News Network is a U.S. cable news channel founded in 1980 by Ted Turner. Upon its launch, CNN was the first channel to provide 24-hour television news coverage, and the first all-news television channel in the United States...
article from July 30, 2004 (accessed 10/06/05.)