Alter (crater)

Alter
Oblique Lunar Orbiter 5 image, facing west
Coordinates18°44′N 107°48′W / 18.74°N 107.80°W / 18.74; -107.80
Diameter64.73 km (40.22 mi)
DepthUnknown
Colongitude108° at sunrise
EponymDinsmore Alter
Satellite craters of Alter

Alter is a lunar impact crater that is located in the northern hemisphere on the far side of the Moon. It lies to the southwest of the larger crater Robertson, and to the east of Ohm.

The outer rim of Alter has been degraded by subsequent erosion, most notably at the northern and southern extremes. There is a small crater lying across the south-southeast rim. A cleft runs across the floor from the southern rim toward the north-northeast. Ray material cross the crater floor from the east, forming a pair of faint bands.

Prior to formal naming by the IAU in 1970,[1] Alter was called Crater 257.[2] The crater Alter W, to the northwest of Alter, was called Crater 255. A crater that is currently unnamed, between Alter W and Comrie K, was called Crater 254.

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 Alter.

Alter[3] Latitude Longitude Diameter
K 16.3° N 106.0° W 22 km
W 20.4° N 109.2° W 52 km

References

  1. ^ Alter, Gazetteer of Planetary Nomenclature, International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN)
  2. ^ Lunar Farside Chart (LFC-1A), 2nd Edition October 1967
  3. ^ Bussey, B.; Spudis, P. (2004). The Clementine Atlas of the Moon. New York: Cambridge University Press. p. 291. ISBN 978-0-521-81528-4.
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