Worn walls and a nearly flat floor

Feature Profile & Selenographic Data

Feature type

crater

Coordinates

27.60° N · 55.50° E

Diameter

130.77 km

IAU approval

1935/01/01 00:00:00

LAC quadrangle

LAC-44 · Cleomedes

Geological Period

Nectarian

Geological Chronicle

Cleomedes lies north of Mare Crisium, among rough ground marked by multiple crater impacts. Tralles intrudes into the northwest rim. The outer wall is heavily worn and eroded, especially in the south.

The floor is nearly flat. A small central peak sits north of its midpoint and forms a linear ridge toward the north-northeast; the peak’s infrared spectrum has been identified as pure crystalline plagioclase. Several craterlets mark the floor, including a pair of overlapping craters just inside the northwest rim.

Rima Cleomedes crosses the northern floor from the northwest rim toward the southeast, branching in a fork after it passes the crater mid-line. Smaller clefts lie in the southeast part of the floor, and a pair of lunar domes has been identified south of Cleomedes.

The crater is named for the Greek astronomer Cleomedes. Giovanni B. Riccioli included the name in lunar nomenclature in 1651. The International Astronomical Union formally adopted the designation in 1935.

Chronology & Exploration

1. Nectarian Nectarian crater

   Cleomedes is one of the largest craters of Nectarian age.

2. 1651 Name enters lunar nomenclature

   Italian astronomer Giovanni B. Riccioli included the name Cleomedes in lunar nomenclature.

3. 1935 Designation adopted

   The International Astronomical Union formally adopted the designation.

Scientific Sources & References

• International Astronomical Union — Registry coordinates and diameter.
• Wikipedia — Landform, surface features, and naming history.

Name Origin

Greek astronomer (unkn-c. 50 B.C.).