Gibbs is a lunar

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

that lies near the eastern limb of the

Moon The Moon is Earth's only natural satellite. It Orbit of the Moon, orbits around Earth at Lunar distance, an average distance of (; about 30 times Earth diameter, Earth's diameter). The Moon rotation, rotates, with a rotation period (lunar ...

. It is situated less than a crater diameter to the northeast of the larger crater Hecataeus. The crater chain Catena Humboldt passes to the south of Gibbs, following a line to the northeast. Due to its proximity to the limb, this crater appears foreshortened when viewed from the

Earth Earth is the third planet from the Sun and the only astronomical object known to Planetary habitability, harbor life. This is enabled by Earth being an ocean world, the only one in the Solar System sustaining liquid surface water. Almost all ...

, and visibility is subject to

libration In lunar astronomy, libration is the cyclic variation in the apparent position of the Moon that is perceived by observers on the Earth and caused by changes between the orbital and rotational planes of the moon. It causes an observer to see ...

Description

The outer rim of Gibbs is not quite circular, and an outward bulge to the north gives it an

onion An onion (''Allium cepa'' , from Latin ), also known as the bulb onion or common onion, is a vegetable that is the most widely cultivated species of the genus '' Allium''. The shallot is a botanical variety of the onion which was classifie ...

-like profile. The southeastern wall is slightly straightened and there is a low break in the rim at the southern and northern ends. In other respects, however, the rim is only slightly eroded. The interior floor is nearly level in the southwestern half, with irregular ridges to the northeast. There is a small craterlet to the northwest of the midpoint.

Etymology

The crater was named after Josiah W. Gibbs by the IAU in 1964. The crater Mirzakhani was named to honor Iranian mathematician

Maryam Mirzakhani Maryam Mirzakhani (, ; 12 May 1977 – 14 July 2017) was an Iranian mathematician and a professor of mathematics at Stanford University. Her research topics included Teichmüller space, Teichmüller theory, hyperbolic geometry, ergodic the ...

, in 2024.

Nearby features

A recent small impact along the northeastern rim, Mirzakhani, has produced a small

ray system In planetary geology, a ray system comprises radial streaks of fine '' ejecta'' thrown out during the formation of an impact crater, looking somewhat like many thin spokes coming from the hub of a wheel. The rays may extend for lengths up to ...

that forms a skirt of higher

albedo Albedo ( ; ) is the fraction of sunlight that is Diffuse reflection, diffusely reflected by a body. It is measured on a scale from 0 (corresponding to a black body that absorbs all incident radiation) to 1 (corresponding to a body that reflects ...

material across this part of the rim. Faint traces from these rays cover the interior floor of Gibbs. The area around the Mirzakhani impact is characterised by an extremely high

rockfall A rockfall or rock-fallWhittow, John (1984). ''Dictionary of Physical Geography''. London: Penguin, 1984. . is a quantity of Rock (geology), rock that has fallen freely from a cliff face. The term is also used for collapse of rock from roof or wa ...

density by lunar standards. The satellite crater Gibbs D has a diameter of and is located at 13.1° S, 85.9° E.

Imagery

rim of Gibbs crater AS15-81-10920.jpg, Oblique closeup of the recent small impact on the north rim of Gibbs, from

Apollo 15 Apollo 15 (July 26August 7, 1971) was the ninth crewed mission in the Apollo program and the fourth Moon landing. It was the first List of Apollo missions#Alphabetical mission types, J mission, with a longer stay on the Moon and a greate ...

Gibbs crater AS17-P-3152.jpg, Oblique view from

Apollo 17 Apollo 17 (December 7–19, 1972) was the eleventh and final mission of NASA's Apollo program, the sixth and most recent time humans have set foot on the Moon. Commander Gene Cernan and Lunar Module Pilot Harrison Schmitt walked on the Moon, ...

Gibbs D crater AS15-M-1883.jpg, Gibbs D from Apollo 15

References

* * * * * * * * * * * * {{refend category:impact craters on the Moon

Description

Etymology

Nearby features

Imagery

See also

References