Hortensius (crater)
Encyclopedia
Hortensius is a small, bowl-shaped lunar
impact crater
that is located in the northern part of the Mare Insularum
. It lies some distance to the west-southwest of the prominent crater Copernicus
. Hortensius is circular and cup-shaped, with a small floor at the mid-point of the sloping interior walls. The interior has a higher albedo
than the surrounding lunar mare
, despite traces of ray material
from Copernicus.
To the north of this feature is a collection of six lunar dome
s, many having a tiny craterlet at the summit. These are shield volcano
es that were formed by a highly viscous type of lava
. 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.
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...
impact crater
Impact crater
In the broadest sense, the term impact crater can be applied to any depression, natural or manmade, resulting from the high velocity impact of a projectile with a larger body...
that is located in the northern part of the Mare Insularum
Mare Insularum
Mare Insularum is a lunar mare located in the Insularum basin just south of Mare Imbrium. The basin material is of the Lower Imbrian epoch, with the mare material of the Upper Imbrian epoch. The mare is bordered by the craters Copernicus on the east, and Kepler on the west...
. It lies some distance to the west-southwest of the prominent crater Copernicus
Copernicus (lunar crater)
Copernicus is a prominent lunar impact crater named after the astronomer Nicolaus Copernicus, located in eastern Oceanus Procellarum. It is estimated to be about 800 million years old, and typifies craters that formed during the Copernican period in that it has a prominent ray system.-...
. Hortensius is circular and cup-shaped, with a small floor at the mid-point of the sloping interior walls. The interior has a higher albedo
Albedo
Albedo , or reflection coefficient, is the diffuse reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it...
than the surrounding lunar mare
Lunar mare
The lunar maria are large, dark, basaltic plains on Earth's Moon, formed by ancient volcanic eruptions. They were dubbed maria, Latin for "seas", by early astronomers who mistook them for actual seas. They are less reflective than the "highlands" as a result of their iron-rich compositions, and...
, despite traces of ray material
Ray system
A ray system comprises radial streaks of fine ejecta thrown out during the formation of an impact crater, looking a bit like many thin spokes coming from the hub of a wheel. The rays can extend for lengths up to several times the diameter of their originating crater, and are often accompanied by...
from Copernicus.
To the north of this feature is a collection of six lunar dome
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 wide, rounded, circular features with a gentle slope...
s, many having a tiny craterlet at the summit. These are shield volcano
Shield volcano
A shield volcano is a type of volcano usually built almost entirely of fluid lava flows. They are named for their large size and low profile, resembling a warrior's shield. This is caused by the highly fluid lava they erupt, which travels farther than lava erupted from more explosive volcanoes...
es that were formed by a highly viscous type of lava
Lava
Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...
. 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 mid-point that is closest to Hortensius.| Hortensius | Latitude | Longitude | Diameter (km) | Diameter (mi) |
|---|---|---|---|---|
| A | 4.4° N | 30.7° W | 10 km | 6 mi |
| B | 5.3° N | 29.5° W | 6 km | 4 mi |
| C | 6.0° N | 26.7° W | 7 km | 4 mi |
| D | 5.4° N | 32.3° W | 6 km | 4 mi |
| E | 5.2° N | 25.4° W | 15 km | 9 mi |
| F | 7.1° N | 25.6° W | 6 km | 4 mi |
| G | 8.1° N | 26.1° W | 4 km | 2½ mi |
| H | 5.9° N | 31.1° W | 6 km | 4 mi |