Werner is a prominent lunar

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

that lies in the rugged south-central highlands of the

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

. It was named after the 15th-century German mathematician and astronomer

Johannes Werner Johann(es) Werner ( la, Ioannes Vernerus; February 14, 1468 – May 1522) was a German mathematician. He was born in Nuremberg, Germany, where he became a parish priest. His primary work was in astronomy, mathematics, and geography, although he ...

. It is almost joined with the crater Aliacensis to the southeast, and the pair form a rugged valley in the intervening gap. Due west of Werner is the distorted

Regiomontanus Johannes Müller von Königsberg (6 June 1436 – 6 July 1476), better known as Regiomontanus (), was a mathematician, astrologer and astronomer of the German Renaissance, active in Vienna, Buda and Nuremberg. His contributions were instrumenta ...

, and to the north is the remains of Blanchinus. It is from the

Eratosthenian The Eratosthenian period in the lunar geologic timescale runs from 3,200 million years ago to 1,100 million years ago. It is named after the crater Eratosthenes, which displays characteristics typical of craters of this age, including a surface ...

period, which lasted from 3.2 to 1.1 billion years ago. The rim of Werner shows little appearance of wear, and is much younger and less eroded than the other large craters in the surroundings. The interior wall is

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 ...

d, and there is a noticeable rampart on the exterior. There are several low rises on the crater floor and a notable central peak. Its highly terraced walls attain peaks of almost 1,500 feet. The crater is 45 miles (70 kilometers) in diameter, and the difference in height between its rim and its deepest parts is 4.2 kilometers.''Autostar Suite Astronomer Edition''. CD-ROM. Meade, April 2006. Near the Werner crater, a chiaroscuro effect created by the dark craters and their lit rims is visible for several hours before first quarter forms an X.

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 Werner.

References

External links

*{{Commons category-inline Impact craters on the Moon Eratosthenian