Vallis Alpes and Cassini
Posted 22 February 2013 - 09:32 AM
Posted 22 February 2013 - 09:49 AM
I have also seen this rille captured with a 4"apo as well (Ron Bee?). It was also well known during the visual era, recorded (albeit always very inaccurately) by observers using the smaller (6inch) achromats popular in that era (late 19th century). the larger portions are ~600-700m width so what is really needed is good seeing (~1"ac) and an optimal sun angle.
Posted 22 February 2013 - 11:02 AM
Requiring simultaneously good seeing and the right sun angle does make it a challenge indeed. The rille and Plato craterlets are fun things to do on the moon. I found I got a better craterlet count two days after getting a glance at the rille. Will try again next month if the cloud lords can bugger off.
Posted 22 February 2013 - 08:21 PM
Posted 22 February 2013 - 08:38 PM