A lunar dome is a type of

shield volcano A shield volcano is a type of volcano named for its low profile, resembling a warrior's shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more v ...

that is found on the surface of the

Earth Earth is the third planet from the Sun and the only astronomical object known to harbor life. While large volumes of water can be found throughout the Solar System, only Earth sustains liquid surface water. About 71% of Earth's surfa ...

Moon The Moon is Earth's only natural satellite. It is the fifth largest satellite in the Solar System and the largest and most massive relative to its parent planet, with a diameter about one-quarter that of Earth (comparable to the width of ...

. They are typically formed by highly viscous, possibly

silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one ...

-rich

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

, erupting from localized vents followed by relatively slow cooling. Lunar domes are wide, rounded, circular features with a gentle slope rising in elevation a few hundred meters to the midpoint. They are typically 8–12 km in diameter, but can be up to 20 km across. Some of the domes contain a small craterlet at the peak. Some of the domes have been shown to consist of the same materials as the

lunar maria The lunar maria (; singular: mare ) are large, dark, basaltic plains on Earth's Moon, formed by ancient asteroid impacts on the far side on the Moon that triggered volcanic activity on the opposite (near) side. They were dubbed , Latin for 'seas' ...

. Thus they could be created by some mechanism that differs from the mare-forming flows. It is thought that these domes are formed from a smaller

magma chamber A magma chamber is a large pool of liquid rock beneath the surface of the Earth. The molten rock, or magma, in such a chamber is less dense than the surrounding country rock, which produces buoyant forces on the magma that tend to drive it upw ...

that is closer to the surface than is the case for a mare. This results in a lower pressure, and so the lava flows more slowly. The

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...

wells up through a crack in the surface, but the flow eventually concentrates through one primary vent. This concentration can then result in a vent crater at the peak of the dome. The cluster of lunar domes at the

Marius Hills The Marius Hills are a set of volcanic domes located in Oceanus Procellarum on Earth's Moon. The domes are thought to have formed from lavas fairly more viscous than those that formed lunar mares. These domes average approximately in height. Th ...

was considered as a possible landing site of

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

. There are concentrations of lunar domes near the craters

Hortensius Quintus Hortensius Hortalus (114–50 BC) was a famous Roman lawyer, a renowned orator and a statesman. Politically he belonged to the Optimates. He was consul in 69 BC alongside Quintus Caecilius Metellus Creticus. His nickname was ''Dionysia'', ...

, and T. Mayer, across the top of

Mons Rümker Mons Rümker is an isolated volcanic formation that is located in the northwest part of the Moon's near side, at selenographic coordinates 40.8° N, 58.1° W. The feature forms a large, elevated mound in the northern part of the Oceanus Procellaru ...

, and in

Mare Fecunditatis Mare Fecunditatis (Latin ''fēcunditātis'', the "Sea of Fecundity" or "Sea of Fertility") is a lunar mare in the eastern half of the visible Moon. The mare has a maximum diameter of 840 km. __NOTOC__ Description The Fecunditatis basin forme ...

. Solitary lunar domes are also found, including Kies Pi (π), Milichius Pi (π),

Mons Gruithuisen Gamma Mons Gruithuisen Gamma (γ) is a lunar dome 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 gen ...

(γ) and Delta (δ), and domes near the craters Gambart C,

Beer Beer is one of the oldest and the most widely consumed type of alcoholic drink in the world, and the third most popular drink overall after water and tea. It is produced by the brewing and fermentation of starches, mainly derived from ce ...

, and Capuanus. Omega Cauchy (ω) and Tau Cauchy (τ) form a pair of domes near the crater

Cauchy Baron Augustin-Louis Cauchy (, ; ; 21 August 178923 May 1857) was a French mathematician, engineer, and physicist who made pioneering contributions to several branches of mathematics, including mathematical analysis and continuum mechanics. He w ...

. Likewise near Arago are the domes Arago Alpha (α) and Arago Beta (β). There are two domes south of

Mons Esam Mons Esam is a small, isolated mountain in the northern part of the Mare Tranquillitatis. It is located to the southeast of the crater Vitruvius and to the west-northwest of Lyell. To the northeast of this ridge is the bay called Sinus Amoris. ...

. The

IAU The International Astronomical Union (IAU; french: link=yes, Union astronomique internationale, UAI) is a nongovernmental organisation with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach ...

does not currently have rules that establish the naming of lunar domes, but the practice in the professional literature and in lunar sciences is to name the dome with the name of the nearest crater followed by a number that denotes the order of discovery.

Examples

File:Donna crater Omega Cauchy as08-13-2344hr.jpg, Omega Cauchy, with the small crater

Donna Donna may refer to the short form of the honorific ''nobildonna'', the female form of Don (honorific) in Italian. People * Donna (given name); includes name origin and list of people and characters with the name * Roberto Di Donna (born 1968), ...

at its summit,

Mare Tranquillitatis Mare Tranquillitatis (Latin ''tranquillitātis'', the Sea of Tranquillity or Sea of Tranquility; see spelling differences) is a lunar mare that sits within the Tranquillitatis basin on the Moon. It is the first location on another world to be ...

File:Lunar dome AS11-42-6317.jpg, Oblique view of a dome north of Sinas,

File:Lunar dome near Messier crater 5038 med.jpg, Oblique view of lunar dome near Messier in

. Note dark 'halo' deposits. The crater left of center is unrelated (formed after the dome). File:Lunar dome AS15-M-0424.jpg, Lunar dome south of

Mare Imbrium Mare Imbrium (Latin ''imbrium'', the "Sea of Showers" or "Sea of Rains", "Sea of Tears") is a vast lava plain within the Imbrium Basin on the Moon and is one of the larger craters in the Solar System. The Imbrium Basin formed from the colli ...

File:Lunar domes Hortensius area 3123 h2.jpg, Oblique view of three of the six lunar domes north of

, from

Lunar Orbiter 3 The Lunar Orbiter 3 was a spacecraft launched by NASA in 1967 as part of the Lunar Orbiter program, Lunar Orbiter Program. It was designed primarily to photograph areas of the Moon, lunar surface for confirmation of safe landing sites for the S ...

File:Hortensius Domes (LRO).png, LRO image of the Hortensius domes File:Volcanoes in Lacus Veris (30x30km) 2.png, Domes in

Lacus Veris Lacus Veris (Latin ''vēris'', "Lake of Spring") is a small lunar mare on the Moon. In selenographic coordinates, the mare centered at 16.5° S, 86.1° W and is approximately 396 km long. The mare extends along an irregular 90° arc from ea ...

, Orientale basin File:Mons Gruithuisen 4145 h1.jpg, Mons Gruithuisen Gamma (left) and Delta (right), from

Lunar Orbiter 4 Lunar Orbiter 4 was a robotic U.S. spacecraft, part of the Lunar Orbiter program, Lunar Orbiter Program, designed to orbit the Moon, after the three previous orbiters had completed the required needs for Project Apollo, Apollo mapping and site s ...

References

* Lionel Wilson and James W. Head,
Lunar Gruithuisen and Mairan domes: Rheology and mode of emplacement
, ''Journal of Geophysical Research'', vol. 108, 2003. * Lena, R., Wöhler, C., Phillips, J., Chiocchetta, M.T., "Lunar Domes:Properties and Formation Processes", "Springer Praxis Books", 2013,

.

External links

Marvin W. Huddleston, ALPO Lunar Dome Survey Coordinator's web page on Lunar DomesGLR Group Website
{{The Moon Volcanoes on the Moon, Shield volcanoes *Lunar dome Geologic domes

Examples

See also

References

External links