Also known as: Posidonius crater
Date/time: 2016.03.14. 16:30-16:40 UT
Equipment: 235/1280 OptiScope, dobsonian mount,
+ Scopium SWA 15,10 ; Planetary 5mm
Col. : 342.5°
Location: Zákány, Hungary N46°14′ 59,2” E16°57′ 15,3”
Observer: Tamás Bognár
Media : Wood-free drawing paper, H and HB pencil.
Posidonius is a lunar impact crater that is located on the north-eastern edge of Mare Serenitatis, to the south of Lacus Somniorum. The crater Chacornac is attached to the southeast rim, and to the north is Daniell.
The rim of Posidonius is shallow and obscured, especially on the western edge, and the interior has been overlain by a lava flow in the past. The crater ramparts can still be observed to the south and east of the crater rim, and to a lesser degree to the north.
There is a smaller, semi-circular rim of a concentric, flooded crater within the main rim, offset towards the eastern edge. There is no central peak, but the floor is hilly and laced with a rille system named the Rimae Posidonius. The floor is also slightly bulged due to the past lava uplift, which also likely produced the complex of rilles. The northeast rim is interrupted by the smaller crater Posidonius B. Within the crater rim, offset just to the west of center is another smaller crater Posidonius A.
Interest : Exceptional formation
Observation period: 5 days after New Moon or 4 days after Full Moon
Minimal Instrument: 50 mm refractor