Sea / bay

Mare Fecunditatis

The Sea of Fertility occupies part of the southeastern near side. Its dark surface helps outline craters along the edge.

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Mare Fecunditatis and surrounding lunar terrain in the LROC Wide Angle Camera mosaic
Mare Fecunditatis · North up, east right. Open image ↗
NASA / GSFC / Arizona State University · LROC WAC mosaic via USGS. Regional map crop; lighting is fixed and does not follow the selected date.
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Lunar north up, with geocentric libration. Full atlas mode shows the entire facing surface; switch to Selected phase for today’s illumination. Choose a different date in the atlas.

How to observe Mare Fecunditatis

Start with Langrenus on the eastern margin. Move toward the smaller crater pair Messier and Messier A for a harder challenge.

Finding the region

Look at 7.83° S, 53.67° E on the lunar disc. The chart marker identifies the catalogue centre. Start with a wide field and use the nearby formations below as landmarks.

Equipment & conditions

These dark plains are a good starting point with binoculars. Trace their shapes at low power, then examine the boundary with the brighter highlands. Higher sunlight helps reveal brightness differences; low sunlight brings out ridges.

Lighting

For surface relief, try a time when the Sun is low over this region. To compare surface brightness and any bright rays, return under higher illumination. The atlas calculates the solar elevation at the formation’s centre for any selected date.

View Mare Fecunditatis in the atlas

IAU / USGS Gazetteer

Official feature record

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Approved name
Mare Fecunditatis
Feature classification
Mare, maria
Catalogue dimension / extent
840.35 km
Centre latitude
7.83° S
Centre longitude
53.67° E
Name origin (Gazetteer)
"Sea of Fecundity."

Coordinates are selenographic, with east-positive longitude. Dimensions are the Gazetteer’s catalogue values; for extended formations they do not represent a circular crater diameter. Data snapshot: 2026-09-16. Observing guidance above is separate from the official record.

Nearby formations

The four closest catalogue entries, measured from their centres.

LROC photograph of LangrenusImpact crater

Langrenus

A conspicuous crater along the eastern edge of Mare Fecunditatis. The dark mare forms a helpful background for locating the brighter crater.

LROC photograph of PetaviusImpact crater

Petavius

A large crater near the southeastern limb with a prominent central mountain complex. Its position makes its appearance sensitive to viewing geometry.

LROC photograph of Mare NectarisSea / bay

Mare Nectaris

The Sea of Nectar is a compact dark plain southeast of the main central maria. The adjoining highlands contain a striking chain of large craters.

LROC photograph of Mare CrisiumSea / bay

Mare Crisium

The Sea of Crises is a distinct dark plain near the eastern limb, separated from the main network of maria.