A north–south ridge marks Hahn’s crater floor

Feature Profile & Selenographic Data

Feature type

crater

Coordinates

31.22° N · 73.55° E

Diameter

87.49 km

IAU approval

1935/01/01 00:00:00

LAC quadrangle

LAC-45 · Hubble

Geological Period

Early Imbrian

Geological Chronicle

Hahn lies near the Moon’s northeastern limb. From Earth it appears oval because of foreshortening. Berosus, a slightly smaller crater, is less than one crater diameter to the northwest.

The formation dates to the Early Imbrian epoch. Its inner wall has a system of terraces, especially in the southern half. A smaller crater cuts across the northwest rim, leaving a break that reaches the floor.

A region of lower albedo makes the northern floor darker than the southern section. At the midpoint, an elongated central ridge runs north–south, with several tiny craterlets also marking the floor.

The name honors Friedrich von Hahn, a German astronomer, and Otto Hahn, a German chemist. Giovanni Riccioli applied the name Berosus to the crater in 1651; Johann Mädler later changed it to Hanh.

Chronology & Exploration

1. Early Imbrian Crater dates to this epoch

   Hahn dates to the Early Imbrian epoch of the lunar geologic timescale.

2. 1651 Berosus name applied

   Giovanni Riccioli applied the name Berosus to the crater in 1651.

3. Undated Name later changed to Hanh

   German astronomer Johann Mädler later changed the crater’s name to Hanh.

Scientific Sources & References

• International Astronomical Union Gazetteer — Registry record for the crater’s identity, coordinates, diameter, quadrangle and name origin.
• Wikipedia: Hahn (crater) — Localized source text for the crater’s setting, morphology, floor features, age and naming history.

Name Origin

Friedrich von; German astronomer (1741-1805); Otto; German chemist (1879-1968).