Sinus Medii

The Central Bay, located at the center of the lunar nearside, marking the intersection of the Moon’s equator and prime meridian.

Visual Description

Sinus Medii appeared as a small, irregular dark patch at the very center of the Moon’s visible face. This mare region sits at the junction of several highland areas and serves as the reference point for lunar coordinates. The bay appeared relatively smooth but smaller and less prominent than the major maria, blending into the surrounding highland terrain.

Notable Features

• Located at lunar coordinates 0°N, 0°E
• Center point of Moon’s nearside
• Small irregular mare patch
• Surrounded by highland terrain
• Reference point for selenographic coordinates

Notes

• Name means “Central Bay”
• Surveyor 6 landed here in 1967
• Historical reference point for lunar mapping
• Best observed around first or last quarter
• Coordinates: 0.0°N, 0.0°E (by definition)