When close to the terminator, youthful Copernician aged Philolaus is a dominating sight in the heavily cratered northwestern highlands above Mare Frigoris . 73 km in diameter and perched atop the ancient Imbrium ejecta filled crater, Philolaus D, it's gleaming inner wall is steep and mountainous. The brightly lit slopes reflect enough light to illuminate one of the offfset peaks on it's rubbly floor, a surprising visage suspended in an otherwise black pool of shadow. Scattered around the crater, ancient large Pre-Nectarian and Pre-Imbrium craters seem to have suffered the same fate as Philolaus D, deeply filled with the debris from the Imbrium impact. To the southwest, the sinusoidal curve of the walls of Philolaus G and an unnamed crater which has obliterated a section of it's southern wall, winds its way to the south.
Subject: Philolaus Rukl: 3
Time: 11:15pm - 12:30 PDT Date: May 4-5, 2009
Seeing: Antoniadi III-IV Weather: clear with winds 5-10 mph occasional cirrus
Lunation: 10.12 days
Colongitude: 38.3 deg.
Lib. in Lat.: +05 deg. 58 min.
Lib. in Long.: +04 deg. 47 min.
Phase: 46.8 deg.
Telescope: 12" Meade SCT f/10
Binoviewer: W.O. Bino-P with 1.6X nosepiece
45 deg. W.O. erect image diagonal
Eyepieces: 18mm W.O. Plossls
Medium:Sketch White and black Conte' on Black Strathmore Artagain paper
Sketch size: 8" X 10"