Messier and Messier A

A unique pair of craters on Mare Fecunditatis, famous for the bright ray system extending westward from Messier A.

Visual Description

Messier and Messier A appeared as a distinctive pair of elongated craters on the floor of Mare Fecunditatis. Messier (to the east) was the smaller of the pair, while Messier A was slightly larger and more elongated. The most striking feature was the pair of bright rays extending westward from Messier A for several hundred kilometers across the dark mare surface, forming a “comet tail” pattern. The unusual double crater and ray system made this one of the Moon’s most recognizable features.

Notable Features

• Unique double crater system
• Elongated crater shapes
• Spectacular westward ray system from Messier A
• “Comet tail” appearance
• Bright rays contrast with dark mare

Notes

• Named after French astronomer Charles Messier
• Possibly formed by low-angle impact or ricochet
• Best observed 4-6 days after new moon
• Coordinates: 1.9°S, 47.6°E
• Classic telescopic target