Ghost Crater & Old Favourites

[cloudsweeper]

4.00am - clear, still, mild - so out with the 10" Bresser.  (Moon 1 day after 3rd quarter, low in SE.)

I started with a couple of favourites by just aiming the Rigel at them and finding them very easily:

Double Cluster - to north, close to trees, but I got a fine view at x35 and just over 2deg.  Switching from the 36mm Baader to the 42mm Rev W/F, the contrast decreased, but rather than blame the EP, I put that down to large and larger values of Exit Pupil.  At x106, I viewed each cluster separately with about 0.6deg of field.  Lovely!

M13, the Great Hercules Globular Cluster - low, east.  I began to resolve stars at x106, better x144, less sharp x211, so I settled for x159 - a fine view, with many outer stars clearly resolved.

(I do like to vary mag by small amounts - having a largeish collection of EPs is I believe quite beneficial.)

On to the star of the session - Luna and the ghost crater Stadius.

The Moon looked beautiful - clear, stable, almost a hemisphere, standing on its jagged terminator like a jellyfish with the initial orientation of viewing.  x35/2deg.  Archimedes was right on the terminator, Copernicus was a little further away with a lit floor and only some shading on the western terraces.  Eratosthenes was closer to the terminator, on the southern edge of M. Imbrium.  A finger of the Apennine Mountains reached out to it from the terminator.

I increased the mag in stages to x254 and noticed fabulous surface detail between Eratosthenes and Copernicus in the form of fine lines of close craterlets in a Y pattern, giving a sort of perforation effect.  Even better, I then spotted at the southern end of this feature a very faint outline of crater Stadius - a ghostly apparition  of an old impact crater, obscured by lava flow.  Easy to miss!  Its perimeter once again showed a perforation effect.  At x318 and in moments of stability, I even noticed some fine and faint pitting in Stadius's southern floor.

An excellent session, just over two hours.  Well worth getting up for, and a great start to the day!

Thanks for reading.

Doug.

 

Edited January 18, 2020 by cloudsweeper

[domstar]

Up at 4 a.m to look at the moon. I like the moon that's dedication. I liked your comment about a 'largeish collection of eyepieces'. It made me smile but at least they get plenty of use. Nice report.

[cloudsweeper]

24 minutes ago, domstar said:

Up at 4 a.m to look at the moon. I like the moon that's dedication. I liked your comment about a 'largeish collection of eyepieces'. It made me smile but at least they get plenty of use. Nice report.

Thanks Dom.  Yes, lots of  EPs (plus a zoom and a Barlow) - Plossls to UWAs and an MWA 100deg - I used ten this morning.  All bases covered -I really don't need any more!  As for 'scopes though.....

Doug.