Astro-Drawings 2001

by Gerhard Niklasch

The Moon

Nasmyth, Wargentin, Schickard

Wargentin

Somewhat schematic drawing of the crater Wargentin, flooded nearly to the rim with Mare lava, in late afternoon light, flanked by Nasmyth to the Southeast and the huge Schickard to the North (Rükl 62, 70).

No attempt has been made to represent the fairly complicated area between Wargentin and Schickard, or detail in the highlands to the West, or structure inside the southern part of Schickard. Instead, I focused on the lighting effects along the edges of Wargentin, and on the terminator encroaching upon the floor of Schickard. The transition from light to shade there was very gradual, indicating gentle curvature. Likewise, the SE corner of Wargentin showed a gentle darkening indicating a slight sloping of the lava surface, and the SE wall had a narrow bright rim. No such rim was detectable along the eastern and NE portions of the wall of Wargentin, and neither was there any shadow on the inside of the W wall, indicating that the interior surface indeed reaches the full height of the rim there.

Clouds were interfering with the observation, and seeing was poor to start with and rapidly deteriorating. Nothing of the wrinkles and ridges on the raised floor of Wargentin was seen.

Drawn 2001 August 16, 03:25-03:35 MEST (01:25-01:35 UT), JD2452137.562
Moon age: 26.24 days, sunrise longitude 127°11', subsolar latitude +1°10'
Libration: long.-5°44', lat.-0°35', limb angle 95°52', tilt 5°.761

Instrument: 8" f/5 Newton, Paracorr; Meade UWA 8.8mm (magnification c.131×)


G. Niklasch / Fri, 17 Aug 2001 05:56:32 MEST