Porter is a

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 circular depression in the surface of a solid astronomical object formed by the hypervelocity impact of a smaller object. In contrast to volcanic craters, which result from explosion or internal collapse, impact crater ...

that is located in the southern part 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 ...

, and lies across the northeastern rim of the huge walled plain

Clavius Christopher Clavius, SJ (25 March 1538 – 6 February 1612) was a Jesuit German mathematician, head of mathematicians at the Collegio Romano, and astronomer who was a member of the Vatican commission that accepted the proposed calendar inve ...

. Although generally circular, the form of this crater has been modified by the geometry of the surface on which it was formed. The outer rim is generally lower to the southwest, where it lies on the floor of Clavius. Likewise the interior floor is flatter near this face. In contrast the northeastern floor is rougher and more uneven in the northeastern half. The crater is somewhat worn in appearance, in comparison with the younger and sharper-edged Rutherfurd to the south along the southeastern rim of Clavius. There is a double central peak located just to the southwest of the midpoint. A small craterlet lies along the northwestern inner wall of the crater, but the formation is not otherwise significantly marked by smaller impacts. This crater was formerly designated Clavius B before being renamed by the

IAU The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...

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 Porter.

References

* * * * * * * * * * * * {{refend Impact craters on the Moon