Humboldt (crater)
Humboldt is a large lunar impact crater that is located near the eastern limb of the Moon. Due to foreshortening this formation has an extremely oblong appearance. The actual shape of the crater is an irregular circle, with a significant indentation along the southeastern rim where the prominent crater Barnard intrudes. To the north-northwest of Humboldt is the large crater Hecataeus. Phillips is attached to the western rim. The rim of Humboldt is low, worn, and irregular in outline. The central peak forms a range on the crater floor. The floor surface contains a network of rilles forming a pattern of radial spokes and concentric arcs. There are also some dark patches located near the walls to the northeast, northwest, and southeast. There is a chain of craters leading from the northwest crater rim to a distance almost as long as the crater is wide. This formation is designated Catena Humboldt. Due to its location near the lunar limb, little detail was known about this crater until it was photographed by orbiting spacecraft (mainly Lunar Orbiter 4).
Coordinates
199.46 km (123.94 mi)
Unknown
254° at sunrise
The crater was named after German philologist Wilhelm von Humboldt by the IAU.[1]
Humboldt is one of the largest craters of Upper (Late) Imbrian age.[2]
The Apollo 12 mission in 1969 obtained many photographs of Humboldt crater. In the photos below, the central peaks appear white because of the high-Sun elevation angle. The arcuate fractures within Humboldt are evidence of the forces working on the surface of the Moon to change the lunar topography.[4]
Regional view
Oblique view of Humboldt from Apollo 15 mapping camera
Eastern crater floor. The mare-type material on the floor contains radial cracks and concentric rilles. A dark-halo area is visible at the lower left corner. Low hills of material that resemble the central peak protrude through the smooth crater floor. Bright-halo craters are also evident. The "doughnut" filling of the crater at the left margin is a rare feature.[5]
![Eastern crater floor. The mare-type material on the floor contains radial cracks and concentric rilles. A dark-halo area is visible at the lower left corner. Low hills of material that resemble the central peak protrude through the smooth crater floor. Bright-halo craters are also evident. The "doughnut" filling of the crater at the left margin is a rare feature.[5]](http://upload.wikimedia.org/wikipedia/commons/thumb/d/db/AS15-93-12641_%2821925322005%29.jpg/287px-AS15-93-12641_%2821925322005%29.jpg)
The Apollo 15 mission in 1971 obtained many more photographs of Humboldt crater.