Cassini (lunar crater)

Cassini is a lunar impact crater that is located in the Palus Nebularum, at the eastern end of Mare Imbrium. The crater was named after astronomers Giovanni Cassini and Jacques Cassini.^[1] 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.

Cassini

LRO image
Coordinates	40.25°N 4.64°E / 40.25; 4.64
Diameter	56.88 km (35.34 mi)
Depth	1.2 km (0.75 mi)
Colongitude	356° at sunrise
Eponym	Giovanni Cassini and Jacques Cassini

Cassini Crater (to the right) in a Selenochromatic Image (Si)

Description

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.

Oblique view from Apollo 15

The crater Cassini, from Lunar Reconnaissance Orbiter data. Inset graph is elevations taken across the green line, from left to right, and includes dips at the locations of subcraters Cassini B (left) and Cassini A (right).

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.

Cassini is a crater of Lower (Early) Imbrian age.^[2]

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

Cassini and its satellite craters taken from Earth in 2012 at the University of Hertfordshire's Bayfordbury Observatory with the telescopes Meade LX200 14" and Lumenera Skynyx 2-1

By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint 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

See also

• Cassini (Martian crater)