Hortensius is a small, bowl-shaped

lunar Lunar most commonly means "of or relating to the Moon". Lunar may also refer to: Arts and entertainment * ''Lunar'' (series), a series of video games * "Lunar" (song), by David Guetta * "Lunar", a song by Priestess from the 2009 album ''Prior t ...

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 is located in the northern part of the

Mare Insularum Mare Insularum (Latin ''īnsulārum'', the "sea of islands") is a lunar mare located in the Insularum basin just south of the western Mare Imbrium. The basin material is of the Lower Imbrian epoch, with the mare material of the Upper Imbrian ep ...

. It was named after 17th century Dutch astronomer

Martin van den Hove Martin (Maarten) van den Hove (Latinized as Martinus Hortensius (Ortensius)) (1605 – 7 August 1639) was a Dutch astronomer and mathematician. His adopted Latin name is a translation of the Dutch ''hof'' ("garden"), in Latin ''horta''. Early l ...

(Latinized as ''Martinus Hortensius''). It lies some distance to the west-southwest of the prominent crater

Copernicus Nicolaus Copernicus (19 February 1473 – 24 May 1543) was a Renaissance polymath who formulated a mathematical model, model of Celestial spheres#Renaissance, the universe that placed heliocentrism, the Sun rather than Earth at its cen ...

. Hortensius is circular and cup-shaped, with a small floor at the midpoint of the sloping interior walls. The interior has a 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 ...

than the surrounding

lunar mare The lunar maria ( ; mare ) are large, dark, basaltic plains on Earth's Moon, formed by lava flowing into ancient impact basins. They are less reflective than the "highlands" as a result of their iron-rich composition, and hence appear dark to ...

, despite traces of ray material from Copernicus. To the north of this feature is a collection of six

lunar dome A lunar dome is a type of shield volcano that is found on the surface of the Earth's Moon. They are typically formed by highly viscous, possibly silica-rich lava, erupting from localized vents followed by relatively slow cooling. Lunar domes are ...

s, many having a tiny craterlet at the summit. These are

shield volcano A shield volcano is a type of volcano named for its low profile, resembling a 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 viscous lava ...

es that were formed by a highly

viscous Viscosity is a measure of a fluid's rate-dependent resistance to a change in shape or to movement of its neighboring portions relative to one another. For liquids, it corresponds to the informal concept of ''thickness''; for example, syrup h ...

type of

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 Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

. The domes are generally circular in form, with a diameter of 6–8 kilometers (4–5 mi), and rising as high as 400 meters (1300 ft). They are formed of the same material as the surrounding mare, although from a different process.

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 Hortensius. File:Hortensius A crater 4133 h1.jpg,

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 ...

image of Hortensius A File:Hortensius E crater 4126 h1.jpg,

image of Hortensius E

References

* * * * * * * * * * * {{refend Impact craters on the Moon