Cassini (lunar crater)
Encyclopedia
Cassini is a lunar
impact crater
that is located in the Palus Nebularum, at the eastern end of Mare Imbrium
. To the northeast is the Promontorium Agassiz, the southern tip of the Montes Alpes
mountain range. South by south-east of Cassini is the crater Theaetetus
. To the northwest is the lone peak Mons Piton
.
The floor of Cassini is flooded, and is likely as old as the surrounding mare
. The surface is peppered with a multitude of impacts, including a pair of significant craters contained entirely within the rim. Cassini A is the larger of these two, and it lies just north-east of the crater center. A hilly ridge area runs from this inner crater toward the south-east. Near the south-west rim of Cassini is the smaller crater Cassini B.
The walls of this crater are narrow and irregular in form but remain intact despite the lava flooding. Beyond the crater rim is a significant and irregular outer rampart.
For unknown reasons, this crater was omitted from early maps of the Moon. This crater is not of recent origin, however, so the omission was most likely an error on the part of the map-makers.
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 Palus Nebularum, at the eastern end of Mare Imbrium
Mare Imbrium
Mare Imbrium, Latin for "Sea of Showers" or "Sea of Rains", is a vast lunar mare filling a basin on Earth's Moon and one of the larger craters in the Solar System. Mare Imbrium was created when lava flooded the giant crater formed when a very large object hit the Moon long ago...
. To the northeast is the Promontorium Agassiz, the southern tip of the Montes Alpes
Montes Alpes
Montes Alpes is a mountain range in the northern part of the Moon's near side. It was named after the Alps in Europe.This range forms the northeastern border of the Mare Imbrium lunar mare. To the west of the range is the level and nearly featureless mare, while on the eastern face is a more rugged...
mountain range. South by south-east of Cassini is the crater Theaetetus
Theaetetus (crater)
Theaetetus is a lunar impact crater that is located to the southeast of the crater Cassini near the eastern edge of Mare Imbrium. It lies just to the west of the Montes Caucasus range, which forms the eastern shore of the mare. To the southwest is the prominent crater Aristillus.The rim of...
. To the northwest is the lone peak Mons Piton
Mons Piton
Mons Piton is an isolated lunar mountain that is located in the eastern part of the Mare Imbrium, to the north-northwest of the crater Aristillus. Due east of Mons Piton is the flooded crater Cassini, and to the west-northwest lies Piazzi Smyth...
.
The floor of Cassini is flooded, and is likely as old as the surrounding 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...
. The surface is peppered with a multitude of impacts, including a pair of significant craters contained entirely within the rim. Cassini A is the larger of these two, and it lies just north-east of the crater center. A hilly ridge area runs from this inner crater toward the south-east. Near the south-west rim of Cassini is the smaller crater Cassini B.
The walls of this crater are narrow and irregular in form but remain intact despite the lava flooding. Beyond the crater rim is a significant and irregular outer rampart.
For unknown reasons, this crater was omitted from early maps of the Moon. This crater is not of recent origin, however, so the omission was most likely an error on the part of the map-makers.
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 Cassini.| Cassini | Latitude | Longitude | Diameter |
|---|---|---|---|
| A | 40.5° N | 4.8° E | 15 km |
| B | 39.9° N | 3.9° E | 9 km |
| C | 41.7° N | 7.8° E | 14 km |
| E | 42.9° N | 7.3° E | 10 km |
| F | 40.9° N | 7.3° E | 7 km |
| G | 44.7° N | 5.5° E | 5 km |
| K | 45.2° N | 4.1° E | 4 km |
| L | 44.0° N | 4.5° E | 6 km |
| M | 41.3° N | 3.7° E | 8 km |
| P | 44.7° N | 1.9° E | 4 km |
| W | 42.3° N | 4.3° E | 6 km |
| X | 43.9° N | 7.9° E | 4 km |
| Y | 41.9° N | 2.2° E | 3 km |
| Z | 43.4° N | 2.3° E | 4 km |