Mons Gruithuisen Gamma

Mons Gruithuisen Gamma
Mons Gruithuisen Gamma (left) and Delta (right)
Lunar Orbiter 4 image
Highest point
Elevation1500 m
ListingLunar mountains
Coordinates36°34′N 40°43′W / 36.56°N 40.72°W / 36.56; -40.72
Geography
Map
LocationNear side of the Moon
Geology
Mountain typeLunar dome
Oblique view from Apollo 15
Oblique view from LRO
Gruithuisen Gamma, Delta and North-West domes as viewed from Earth (8" Dobsonian telescope, untracked). Due to severe foreshortening, Gamma look like an upturned bathtub or loaf of bread.

Mons Gruithuisen Gamma (γ) is a lunar dome[1] that lies to the north of the crater Gruithuisen at the western edge of the Mare Imbrium.

This massif is shaped as a rounded dome in the surface, occupying a diameter of 20 km and climbing gently to a height of over 1500 meters.[2][3] At the crest is a small crater.

This formation appears foreshortened when viewed from the Earth, and it has been described by Antonin Rukl as resembling an "upturned bathtub".[4]

To the east lies the similar Mons Gruithuisen Delta (δ). Together they are often informally called the Gruithuisen domes. To the south of the Gruithuisen domes is a portion of Oceanus Procellarum that was named Sinus Viscositatis [it] by the IAU in December 2022.[5]

The Gruithuisen domes differ from typical mare domes in that they're more mountain-like in their proportions, with a higher albedo and a rougher surface texture. The lava they're composed of might be the key to why they're different. It's thought to have a higher silica content, making it thicker, slower moving and faster cooling, enabling it to pile up into these structures. Such silicic volcanism is rare on the Moon, and it's still unclear how it can occur there at all, as on Earth it requires the presence of water and plate tectonics - factors absent on the Moon.[6] This makes the region a compelling target for exploration.

Mons Gruithuisen Gamma was expected to be the landing site for Peregrine Mission One, which launched on January 8, 2024, on the maiden flight of the Vulcan Centaur rocket, the mission failed due to a leaky valve, precluding any attempt at landing.

  1. ^ Cain, Fraser (July 31, 2006). "What's Up this Week: July 31 – August 6, 2006". Universe Today.
  2. ^ Mons Gruithuisen Gamma, Gazetteer of Planetary Nomenclature, International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN)
  3. ^ LROC Quickmap, DEM contours layer
  4. ^ Rukl, Antonin (2004). Atlas of the Moon. Sky Publishing. p. 201. ISBN 1931559074.
  5. ^ Sinus Viscositatis, Gazetteer of Planetary Nomenclature, International Astronomical Union (IAU) Working Group for Planetary System Nomenclature (WGPSN)
  6. ^ North, A.C. (2024). "Crustal context of the Moon's Gruithuisen domes" (PDF). 55th LPSC. 2621.