Circular formation composing a remarkable trio with
Ptolemaeus and Arzachel. Several observed transcient phenomena whose
a gaseous emission spectra obtained
by Kozyrev in November 1958.
Tormented steep slopes riddled with craterlets.
High walls in terraces.
Flat floor to the North. tormented to the South with black spots.
Central mountain. Craterlets and hills. Contains Rimae Alphonsus.
Dimension: 121x121Km / 71x71Mi
Height: 2730m / 8300ft
Height/Wide ratio: 0.0231
Interest : Exceptional formation
Observation period: First Quarter or 6 days after Full Moon
Minimal Instrument: 10x binoculars