Thales (crater)
Encyclopedia
Thales is a small crater
located in the northeast part of the Moon
, just to the west of the larger crater Strabo
. To the southeast is the walled plain De La Rue
. Thales has a sharp, circular rim that has received little erosion. The lunar surface around Thales has a ray system
that extends for over 600 kilometers. An area to the north-northwest of the crater is free of rays, however, indicating that the crater may have been formed by a low-angle impact from that direction. The inner wall has some terraces, particularly along the southern side. The sides have a higher albedo
than the typical lunar terrain.
This crater has been noted for transient lunar phenomena
. In 1892, E. E. Barnard observed a pale haze fill the crater interior, while the surroundings remained clear and sharply visible.
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 northeast part of the Moon
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...
, just to the west of the larger crater Strabo
Strabo (crater)
Strabo is a lunar crater that is located near the northeastern rim of the Moon. At this angle the crater appears oval in shape due to foreshortening. It is attached to the north rim of the walled plain De La Rue. To the west is the smaller crater Thales...
. To the southeast is the walled plain De La Rue
De La Rue (crater)
De La Rue is the remnant of a lunar crater, or possibly several merged craters, creating a formation sometimes called a walled plain. It lies in the northeastern part of the Moon on the near side, and so appears foreshortened due to its location. This formation lies to the north-northwest of the...
. Thales has a sharp, circular rim that has received little erosion. The lunar surface around Thales has a ray system
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...
that extends for over 600 kilometers. An area to the north-northwest of the crater is free of rays, however, indicating that the crater may have been formed by a low-angle impact from that direction. The inner wall has some terraces, particularly along the southern side. The sides have 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 typical lunar terrain.
This crater has been noted for transient lunar phenomena
Transient lunar phenomenon
A transient lunar phenomenon , or lunar transient phenomenon , is a short-lived light, color, or change in appearance on the lunar surface....
. In 1892, E. E. Barnard observed a pale haze fill the crater interior, while the surroundings remained clear and sharply visible.
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 Thales.| Thales | Latitude | Longitude | Diameter |
|---|---|---|---|
| A | 58.5° N | 40.8° E | 12 km |
| E | 57.2° N | 43.2° E | 29 km |
| F | 59.4° N | 42.1° E | 37 km |
| G | 61.6° N | 45.3° E | 12 km |
| H | 60.3° N | 48.0° E | 10 km |
| W | 58.5° N | 39.8° E | 6 km |