Lalande is a small

lunar Lunar most commonly means "of or relating to the Moon". Lunar may also refer to: Arts and entertainment * ''Lunar'' (series), a series of video games * "Lunar" (song), by David Guetta * "Lunar", a song by Priestess from the 2009 album ''Prior t ...

impact crater An impact crater is a depression (geology), depression in the surface of a solid astronomical body formed by the hypervelocity impact event, impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal c ...

that lies in the central part of the visible

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

, on the eastern edge of

Mare Insularum Mare Insularum (Latin ''īnsulārum'', the "sea of islands") is a lunar mare located in the Insularum basin just south of the western Mare Imbrium. The basin material is of the Lower Imbrian epoch, with the mare material of the Upper Imbrian ep ...

. It was named after French astronomer

Jérôme Lalande Joseph Jérôme Lefrançois de Lalande (; 11 July 1732 – 4April 1807) was a French astronomer, freemason and writer. He is known for having estimated a precise value of the astronomical unit (the distance from the Earth to the Sun) using measu ...

. The crater is surrounded by a high-

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

area of ejecta that extends into a

ray system In planetary geology, a ray system comprises radial streaks of fine '' ejecta'' thrown out during the formation of an impact crater, looking somewhat like many thin spokes coming from the hub of a wheel. The rays may extend for lengths up to ...

with a maximum radius of over 300 kilometers. The interior wall has a

terrace Terrace may refer to: Landforms and construction * Fluvial terrace, a natural, flat surface that borders and lies above the floodplain of a stream or river * Terrace, a street suffix * Terrace, the portion of a lot between the public sidewalk a ...

system, and there is a small central rise at the midpoint of the floor. It was formed during the

Copernican period The Copernican Period in the lunar geologic timescale runs from approximately 1.1 billion years ago to the present day. The base of the Copernican period is defined by impact craters that possess bright optically immature ray systems. The crate ...

of the moon extending from 1.1 billion years ago to the present. Its young age is indicated by the bright rays of ejecta surrounding the crater, its sharp features, and the relative lack of later impacts in its interior. The rays of ejecta from Lalande overlay the ejecta rays from Copernicus Crater, meaning it is younger than Copernicus, and thus no more than 800 million years old. In 2002, a meteorite was discovered in the

Oman Oman, officially the Sultanate of Oman, is a country located on the southeastern coast of the Arabian Peninsula in West Asia and the Middle East. It shares land borders with Saudi Arabia, the United Arab Emirates, and Yemen. Oman’s coastline ...

desert by Edwin Gnos of the

University of Berne The University of Bern (, , ) is a public research university in the Swiss capital of Bern. It 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 progra ...

. This rock, identified as

Sayh al Uhaymir 169 Sayh al Uhaymir 169 (SaU 169) is a 206 gram 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 incompatibl ...

, 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.Gnos, Edwin, ''et al.'', 2004, Pinpointing the Source of a Lunar Meteorite: Implications for the Evolution of the Moon,

Science Science is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into twoor threemajor branches: the natural sciences, which stu ...

30 July 2004: Vol. 305 no. 5684 pp. 657-659 DOI: 10.1126/science.109939
abstract
/ref>

Satellite craters

By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Lalande.

References

* * * * * * * * * * *

External links

Rock traced from Moon crater to Earth
—

CNN Cable News Network (CNN) is a multinational news organization operating, most notably, a website and a TV channel headquartered in Atlanta. Founded in 1980 by American media proprietor Ted Turner and Reese Schonfeld as a 24-hour cable ne ...

article from July 30, 2004 (accessed 10/06/05.) * {{lpi-moonatlas, Lalande
Lalande at The Moon Wiki
Impact craters on the Moon