A worn rim, with a depth estimate of at least 1.7 km

Feature Profile & Selenographic Data

Feature type

crater

Coordinates

3.19° S · 76.16° E

Diameter

100.25 km

IAU approval

1964/01/01 00:00:00

LAC quadrangle

LAC-81 · Ansgarius

Geological Chronicle

Gilbert lies near the Moon’s eastern limb, where it appears foreshortened from Earth and offers limited detail to observers. It sits northwest of the similar-sized walled plain Kästner and west of Mare Smythii.

The crater is a degraded walled plain. Its outer rim has been reshaped by nearby impacts, and the southern rim has almost completely disintegrated into a rolling surface that extends south as a depression. Low ridges cross the relatively level floor toward its southern end.

The eroded rim makes the depth estimate somewhat arbitrary. Apollo topographic data nevertheless supports an estimate of at least 1.7 km around most of the rim; that is a lower bound, not a precise depth measurement.

The feature honors two scientists: American geologist Grove K. Gilbert (1843–1918) and English natural philosopher William Gilbert (c. 1544–1603). The IAU approved the crater’s name in 1964.

Chronology & Exploration

1. Undated Depth estimated from Apollo topography

   Apollo mission topographic data allowed an estimate of at least 1.7 km around most of the crater rim; the source describes the estimate as somewhat arbitrary because the rim is highly eroded.

2. Undated Nearby satellite craters receive names

   The IAU assigned names to nearby satellite craters, including Geissler, Van Vleck, and Weierstrass, formerly identified as Gilbert D, M, and N.

3. 1964 Crater name approved

   The IAU approved the name Gilbert, honoring geologist Grove K. Gilbert and natural philosopher William Gilbert.

Scientific Sources & References

• IAU Gazetteer of Planetary Nomenclature — Official feature registry and coordinates.
• Gilbert (lunar crater) — Description, topographic depth estimate, satellite-crater names, and name approval.

Name Origin

Grove Karl; American geologist (1843-1918), William; English physician and physicist (1544-1603).