David Finnigan is a regular contributor to the SPA Lunar Section. David stems Halesowen in the West Midlands, and uses a 305mm Schmidt Cassegrain telescope, in conjunction with a ZWO ASE 120 MMS camera. David took this excellent image of the Schickard, Wargentin, Nasmyth and Phocylides group of craters, located near the north-west limb of the Moon, on the evening of 6th February, 2020.
This is a fascinating group of craters which never fails to catch the attention the eye of the observer when located close to the terminator of the almost full Moon. The large, northern formation, Schickard, is listed by Rukl as a vast walled plain, with a partially flooded floor, 227 km in diameter. South of Schickard is Nasmyth, named after the renowned Scot James Nasmyth, a pioneer of steam, but also a renowned selenographer. As the eye continues to traverse south, we come to Phocylides, a peak on the eastern wall where Nasmyth and Phocylides meet, throws a distinctive shadow across that region. But the star of the show must be strange Wargentin, this 84 km formation appears to have filled to the rim with lava to form a level ‘plateau’ upon which at least one wrinkle ridge may be made out. On David’s image, Wargentin has been captured as it emerges from the Lunar night.
This area has also caught the attention, on more than one occasion, of Larry Todd, who observes from Dunedin, on the South Island of New Zealand. Larry uses an OMC200 Maksutov Cassegrain telescope, in conjunction with a ZWO 122 camera, and made this image on 15th June, 2019.
This is a cropped smartphone image taken by David Graham on the evening of 6th February 2020, using his 230mm f13.5 Maksutov Cassegrain telescope. Nomenclature has been added to aid identification of the craters under discussion in this report. The ‘elevated plateau’ appearance of Wargentin is quite marked on this image.
Paul Sutherland took the above image on 6th February 2020 from Walmer in Kent, using a Fuji X-T10 camera attached to a 66mm Lightwave refractor. Of interest is an ‘indentation’ on the southern limb of the Moon, caused by the crater Bailly. The image below is a cropped smartphone image of the southern limb of the Moon, also taken by David Graham that same evening using the equipment previously described. Bailly is shown in relation to the Schickard group of craters.
Bailly is described by Rukl as a ‘vast walled plain, 304 km in diameter’. On 6th February 2020, the formation was still largely in shadow, but the rim of crater ‘Bailly B’, within the main crater, was catching the morning Sun.