Ross (lunar crater)

Ross (lunar crater) is a small lunar impact crater located in the northern hemisphere of the Moon's near side, within the vast expanse of Mare Tranquillitatis. It is a relatively fresh formation with a sharp-edged rim and a modest central peak, named jointly for two distinguished scientists: the polar explorer James Clark Ross and the astronomer Frank Elmore Ross. The crater lies to the northwest of the prominent Arago crater and the Arago Alpha and Arago Beta domes, placing it in a region of significant geological interest.

Description

Ross is a well-defined, bowl-shaped crater classified as a simple impact structure. Its inner walls display some slumping and have a higher albedo than the surrounding mare basalt, indicating relative youth and less space weathering. The floor is relatively flat and hosts a small central peak, a common feature in craters of this size formed by the rebound of the crater floor post-impact. It is situated in a relatively smooth part of Mare Tranquillitatis, southeast of the Rima Ariadaeus rille system and west of the landing site of the historic Apollo 11 mission at Statio Tranquillitatis. The region is also noted for nearby geological features like the Lamont formation, which is believed to be a buried mascon (mass concentration) affecting the local gravity field. Observations from missions like Lunar Orbiter 5 and data from the Clementine mission have been used to study its composition and morphology.

Satellite craters

By convention, smaller craters associated with Ross are identified on lunar maps by placing a letter on the side of the crater midpoint that is closest to Ross. These satellite craters provide additional context for the geological history of the area. * Ross A: A small, somewhat eroded crater located to the northeast of Ross. * Ross B: A tiny, cup-shaped crater situated to the west-southwest. * Ross D: Located to the southeast, this crater appears more degraded than Ross itself. * Ross E: A small, shallow depression found to the north-northeast. * Ross G: Situated to the southwest, it lies on the mare plain. The presence and condition of these satellite craters help scientists understand the sequence of impact events and the age of the underlying lava flows in Mare Tranquillitatis, as analyzed during projects like the United States Geological Survey's lunar mapping programs.

Namesake

The crater is jointly named for two notable figures in scientific exploration. James Clark Ross was a renowned British naval officer and polar explorer who led expeditions to the Arctic and Antarctica, discovering the Ross Sea and the Ross Ice Shelf. The second namesake is Frank Elmore Ross, an American astronomer and physicist who made significant contributions to astrophotography and celestial mechanics while working at the Yerkes Observatory and later the Mount Wilson Observatory. He is known for his precise catalog of star positions and proper motions. The dual naming follows the conventions of the International Astronomical Union (IAU), which governs lunar nomenclature and often honors contributors from different fields of science. The name was officially adopted in reference to the IAU's definitive catalog, likely influenced by the earlier work of lunar cartographers like Johann Heinrich von Mädler.

Category:Impact craters on the Moon Category:Mare Tranquillitatis