Posidonius

A floor-fractured crater on the northeastern edge of Mare Serenitatis with a complex interior.

Visual Description

Posidonius appeared as a large crater on the shore of Mare Serenitatis with a notably flat, dark floor that has been partially flooded by lava. The floor showed complex features including ridges and rilles. The walls were prominent but not as high as younger craters, and the floor appeared sunken below the surrounding mare level.

Notable Features

• Large, flat, lava-flooded floor
• Complex rille and ridge systems on the floor
• Located on the edge of Mare Serenitatis
• Floor-fractured crater (FFC) showing volcanic modification
• Contains smaller crater Posidonius A on the floor

Notes

• Named after Greek philosopher Posidonius
• Best observed 6-8 days after new moon
• Excellent example of a floor-fractured crater
• Coordinates: 31.8°N, 30.0°E
• The floor features require telescopic observation