Campbell’s worn rim and dark basalt patch

Feature Profile & Selenographic Data

Feature type

crater

Coordinates

45.57° N · 152.91° E

Diameter

222.48 km

IAU approval

1970/01/01 00:00:00

LAC quadrangle

LAC-31 · Campbell

Geological Period

Pre-Nectarian

Geological Chronicle

Campbell lies in the Moon’s northern far side, southwest of the larger walled plain D’Alembert. Impacts have worn and eroded its rim into an irregular ring of ridges and peaks. Small craters lie along the rim and inner wall, and across the floor; Campbell X lies along the northwest inner rim, while Campbell N is near the southern inner wall.

A broad floor patch was resurfaced by basaltic lava during the Late Imbrian. It has a lower albedo than the surrounding floor, so it appears dark. Its irregular perimeter stretches from the crater’s center toward the western rim. A small crater with a bright ray system impacted just north of the deposit.

Campbell is named for American astronomers William W. Campbell (1862-1938) and Leon Campbell (1881-1951). Before the IAU formally named the crater in 1970, it was called Basin XI.

Chronology & Exploration

1. Pre-Nectarian Crater formation

   Campbell dates to the Pre-Nectarian period of the lunar geologic timescale.

2. Late Imbrian Basalt resurfaces the floor

   A broad floor patch was resurfaced by basaltic lava during the Late Imbrian.

3. 1970 IAU names Campbell

   Before its formal naming by the IAU, Campbell was called Basin XI.

Scientific Sources & References

• IAU Gazetteer of Planetary Nomenclature — Name, coordinates, diameter and name origin.
• Campbell (lunar crater) — Crater setting, surface features and naming history.

Name Origin

Leon; American astronomer (1881-1951); William Wallace; American astronomer (1862-1938).