Seeing was not too good tonight but managed a single video of Fracastorius. Named for Italian astronomer, Girolamo Fracastorio (1483-01553) this crater sinks into the lava field that is Mare Nectaris.
Some largish satellite craters are found around it but they are lettered rather than given individual names - mystery number 1 - as some lunar craters actually share "öwners" eg Adams Crater named for John Couch Adams who calculated the orbit of Neptune, and two American astronomers, Walter Adams and John Adams, the last by the way was the father of legendary landscape photographer, Ansell Adams.
Mystery number 2 is the lack of an official name for the extensive and impressive rille system on the floor of Fracastorius. This has been mentioned by others and the unofficial name, Rimae Fracastorius is used to describe it.
The circled area shows a large lava dome which was probably a source of outflow for local lava.
Further out into the mare is the singular crater, Rosse, named for William Parsons, 3rd Earl of Rosse in Ireland.
The Earl spent a fortune trying to abate his aperture fever and ended up with the "Leviathan of Parsonstown" a 1.8 metre speculum metal mirrored Newtonian mounted inside a huge brick-walled "contraption" that used derricks to raise and lower the scope and was powered by several men who followed the directions of the Earl as he peered into the universe.
Parsons was the first person to show that the "nebulae" in the sky were in many cases collections of stars rather than merely gas, M51 or the Whirlpool Galaxy, being one such.
ZWO 178mm camera, Celestron Edge HD 14". Approx. 5,000 frames stacked in Autostakkert!3 and sharpened in Registax.
Interesting write up on the nomenclature, or lack of, of the Fracastorius region. You have captured some nice detail on the floor of the "drowned" crater, don't think I've seen the rille before, will take more notice next time I point a scope in that direction.
