Regiomontanus (crater)
Encyclopedia
Regiomontanus is an ancient lunar impact crater
located in the southern highlands region to the southeast of Mare Nubium
. It is joined at the chaotic northern rim by the crater Purbach
, and to the south-southeast is Walther
.
The crater is heavily worn from impact erosion, and the rim is irregular, mountainous and distinctly oval in outline. The walls on the southern and western edges have been almost completely degraded. A prominent ridge lies off-center to the northwest, with the small crater Regiomontanus A at its summit. The crater floor is lava
-flooded, and has a number of small crater impacts.
The summit crater Regiomontanus A was once considered proof of volcanic
activity on the Moon. However this feature is actually an impact crater, and is offset slightly from the summit of the central peak.
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 southern highlands region to the southeast of Mare Nubium
Mare Nubium
Mare Nubium is a lunar mare in the Nubium basin on the Moon's near side. The mare is located just to the southeast of Oceanus Procellarum. The actual basin is believed to be of Pre-Nectarian system, with the surrounding basin material being of the Lower Imbrian epoch. The mare material is of the...
. It is joined at the chaotic northern rim by the crater Purbach
Purbach (crater)
Purbach is a large lunar crater located in the rugged southern highlands of the Moon. The distorted crater Regiomontanus is attached to the southern rim. To the northwest is Thebit and just to the northeast lies La Caille....
, and to the south-southeast is Walther
Walther (crater)
Walther is an ancient lunar impact crater located in the southern highland region of the Moon. It is joined along the western rim to the crater Deslandres...
.
The crater is heavily worn from impact erosion, and the rim is irregular, mountainous and distinctly oval in outline. The walls on the southern and western edges have been almost completely degraded. A prominent ridge lies off-center to the northwest, with the small crater Regiomontanus A at its summit. The crater floor is 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...
-flooded, and has a number of small crater impacts.
The summit crater Regiomontanus A was once considered proof of volcanic
Volcano
2. Bedrock3. Conduit 4. Base5. Sill6. Dike7. Layers of ash emitted by the volcano8. Flank| 9. Layers of lava emitted by the volcano10. Throat11. Parasitic cone12. Lava flow13. Vent14. Crater15...
activity on the Moon. However this feature is actually an impact crater, and is offset slightly from the summit of the central peak.
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 Regiomontanus.| Regiomontanus | Latitude | Longitude | Diameter |
|---|---|---|---|
| A | 28.0° S | 0.6° W | 6 km |
| B | 29.0° S | 3.7° W | 10 km |
| C | 28.7° S | 5.2° W | 8 km |
| E | 28.2° S | 6.2° W | 6 km |
| F | 27.8° S | 1.9° W | 11 km |
| G | 28.2° S | 3.6° W | 5 km |
| H | 28.6° S | 4.0° W | 6 km |
| J | 29.4° S | 1.9° W | 8 km |
| K | 30.3° S | 0.0° W | 6 km |
| L | 29.7° S | 1.1° E | 6 km |
| M | 29.6° S | 2.1° W | 5 km |
| N | 28.9° S | 0.1° E | 3 km |
| R | 28.4° S | 0.0° W | 3 km |
| S | 28.6° S | 2.0° W | 4 km |
| T | 28.1° S | 2.9° W | 5 km |
| U | 27.9° S | 3.5° W | 11 km |
| W | 29.5° S | 1.4° W | 3 km |
| Y | 30.1° S | 1.6° W | 5 km |
| Z | 27.5° S | 3.0° W | 6 km |