Rilles In Mare Humorum And Gassendi

[cloudsweeper]

Although it was not as clear as in recent evenings, I nevertheless set up the Bresser Dob to view Luna - waxing gibbous, 3 days to full.  After a while it was dark enough to see detail clearly.  Transparency was not great however.

The terminator was west of Mare Humorum, and Gassendi to the north.  The Doppelmayer Rilles (130km [80 miles] crack) were clear at the western edge of MH.  The view was steady between x190 and x254, being very sharp at the lower end.  I noticed two close, parallel cracks, although I believe that sources indicate one main line.  At x318, viewing was difficult - seeing, focusing, 'scope wobble, and drift.

Three peaks in the middle of Gassendi were of course easy, but I hoped to detect some of the fractures/rilles which criss-cross its floor.  I ranged between x115 and x318, and at the lower end, briefly noticed signs of these, using AV.

To finish, I enjoyed some general lunar views - beautifully framed at x64; then the much spoken-of clarity, detail, and texture in the terminator region at x127/159.

Two and a half hours very well spent!

Doug.

Edited May 16, 2019 by cloudsweeper

[John]

Nice report again Doug.

I had my 12 inch dob on the same targets. Seeing less steady than previous nights here but I managed to see some of the Gassendi rilles quite well.

Tonight I could not usefully use more than 265x whereas the previous couple of nights I've been at 320-400x for a lot of the time on the moon.

My turn for some wobbly atmosphere !

[Davey-T]

Encouraged by you guys I aimed the 6" frac at the Moon now I'm blind in one eye  got a filter somewhere must have a look for it tomorrow.

Dave

[John]

1 hour ago, Davey-T said:

Encouraged by you guys I aimed the 6" frac at the Moon now I'm blind in one eye  got a filter somewhere must have a look for it tomorrow.

Dave

Up the power - it dims the surface brightness.

Tonight I used the 12 inch again to observe the moon, without a filter as I usually do. That has 4x the light grasp of your 6 inch.

It is a personal thing though.

[cloudsweeper]

3 hours ago, John said:

Up the power - it dims the surface brightness.

Tonight I used the 12 inch again to observe the moon, without a filter as I usually do. That has 4x the light grasp of your 6 inch.

It is a personal thing though.

Similar here - I was using 10 inches of aperture and no filter, and was only briefly operating at low mag.  Glare is not usually a worry, especially before the sky has become really dark.

Doug.

[alan potts]

Nice report Doug, I have managed to see detail in this crater with my 18 inch, which sort of reminds me it's about time it came out and looked at some light, since doing a bit of AP I tend to have forgotten it. At the moment weather here is awful, cloud, rain and storms to come now for 4 days.

Alan

[niallk]

Nice report!  I have plans to observe the moon over the course of the summer - I've never done it in a semi-methodical way before, just random touring.  It will be unfiltered in a 15" dob  initially dazzling, but I've not been blinded yet!