Galilaei (lunar crater)
Encyclopedia
Galilaei is a lunar impact crater
located in the western Oceanus Procellarum
. Some distance to the southeast is the crater Reiner
, while to the south-southwest is Cavalerius
. Northeast of the crater is a meandering rille
named the Rima Galilaei. To the southeast is the unusual Reiner Gamma
formation, a swirling arrangement of light-hued ray-like
material.
Galilaei is relatively undistinguished, with a sharp-edged rim that has a higher albedo
than the surrounding maria. The inner walls slope down to a ring of debris on the outer edges of the interior floor. There is a small central rise near the mid-point.
About 40 kilometers to the south is the landing site of the Luna 9
robotic probe, the first such vehicle to make a controlled landing on the lunar surface.
Despite being the first person to publish astronomical observations of the Moon with a telescope
, Galileo Galilei
is honored only with this unremarkable formation.
Initially, the name Galilaeus had been applied by Giovanni Battista Riccioli
, an Italian
Jesuit who produced one of the first detailed maps of the Moon in 1651, to a large and bright nearby albedo feature (now known as Reiner Gamma
). The name was transferred to its present location by Johann Heinrich Mädler in his influential Mappa Selenographica, published in collaboration with Wilhelm Beer in four parts between 1834 and 1836. Mädler's motive for this change was the fact that his lunar map did not name albedo features, forcing him to transfer Galileo's name to an insignificant nearby 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...
located in the western Oceanus Procellarum
Oceanus Procellarum
Oceanus Procellarum is a vast lunar mare on the western edge of the near side of the Earth's Moon. Its name derives from the old superstition that its appearance during the second quarter heralded bad weather...
. Some distance to the southeast is the crater Reiner
Reiner (crater)
Reiner is a lunar impact crater on the Oceanus Procellarum, in the western part of the Moon. It has a nearly circular rim, but appears oval in shape due to foreshortening. The rim edge is well-defined and has not been eroded by impacts. In the mid-point of the irregular crater floor is a central peak...
, while to the south-southwest is Cavalerius
Cavalerius (crater)
Cavalerius is a prominent lunar impact crater that lies on the western edge of the Oceanus Procellarum lunar mare on the west part of the visible Moon. It nearly joins the northern rim of Hevelius to the south....
. Northeast of the crater is a meandering rille
Rille
Rille is typically used to describe any of the long, narrow depressions in the lunar surface that resemble channels. Typically a rille can be up to several kilometers wide and hundreds of kilometers in length...
named the Rima Galilaei. To the southeast is the unusual Reiner Gamma
Reiner Gamma
Reiner Gamma is an albedo feature that is located on the Oceanus Procellarum, to the west of the crater Reiner on the Moon. The center of the formation is located at selenographic coordinates . It has an overall dimension of about 70 kilometres...
formation, a swirling arrangement of light-hued ray-like
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...
material.
Galilaei is relatively undistinguished, with a sharp-edged rim that 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 maria. The inner walls slope down to a ring of debris on the outer edges of the interior floor. There is a small central rise near the mid-point.
About 40 kilometers to the south is the landing site of the Luna 9
Luna 9
Luna 9 was an unmanned space mission of the Soviet Union's Luna program. On February 3, 1966 the Luna 9 spacecraft was the first spacecraft to achieve a soft landing on any planetary body other than Earth and to transmit photographic data to Earth.The automatic lunar station that achieved the...
robotic probe, the first such vehicle to make a controlled landing on the lunar surface.
Despite being the first person to publish astronomical observations of the Moon with a telescope
Telescope
A telescope is an instrument that aids in the observation of remote objects by collecting electromagnetic radiation . The first known practical telescopes were invented in the Netherlands at the beginning of the 1600s , using glass lenses...
, Galileo Galilei
Galileo Galilei
Galileo Galilei , was an Italian physicist, mathematician, astronomer, and philosopher who played a major role in the Scientific Revolution. His achievements include improvements to the telescope and consequent astronomical observations and support for Copernicanism...
is honored only with this unremarkable formation.
Initially, the name Galilaeus had been applied by Giovanni Battista Riccioli
Giovanni Battista Riccioli
Giovanni Battista Riccioli was an Italian astronomer and a Catholic priest in the Jesuit order...
, an Italian
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...
Jesuit who produced one of the first detailed maps of the Moon in 1651, to a large and bright nearby albedo feature (now known as Reiner Gamma
Reiner Gamma
Reiner Gamma is an albedo feature that is located on the Oceanus Procellarum, to the west of the crater Reiner on the Moon. The center of the formation is located at selenographic coordinates . It has an overall dimension of about 70 kilometres...
). The name was transferred to its present location by Johann Heinrich Mädler in his influential Mappa Selenographica, published in collaboration with Wilhelm Beer in four parts between 1834 and 1836. Mädler's motive for this change was the fact that his lunar map did not name albedo features, forcing him to transfer Galileo's name to an insignificant nearby crater.
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 Galilaei.| Galilaei | Latitude | Longitude | Diameter |
|---|---|---|---|
| A | 11.7° N | 62.9° W | 11 km |
| B | 11.4° N | 67.6° W | 15 km |
| D | 8.7° N | 62.7° W | 1 km |
| E | 14.0° N | 61.8° W | 7 km |
| F | 12.3° N | 66.2° W | 3 km |
| G | 12.7° N | 67.1° W | 1 km |
| H | 11.5° N | 68.7° W | 7 km |
| J | 13.0° N | 61.9° W | 4 km |
| K | 13.0° N | 62.7° W | 3 km |
| L | 13.2° N | 58.5° W | 3 km |
| M | 13.3° N | 56.8° W | 3 km |
| S | 15.4° N | 64.7° W | 2 km |
| T | 16.2° N | 61.4° W | 2 km |
| V | 17.1° N | 60.3° W | 3 km |
| W | 17.8° N | 60.5° W | 4 km |