Post by Chicago Astronomer - Astro Joe on Mar 23, 2010 3:47:09 GMT -6
Following the Ridge shadows on the crater floor of Ptolemaeus
23 March 2010
23 March 2010
It seemed like a decent early morning to set up the C11 outside of the garage and take some Saturn shots. Not too cold and in the mood.
Unfortunately, Saturn was about to dive behind some tree limbs and I only had about five minutes of imaging time. Not worth it to set up the camera, but I did observe it for a short while - displaying a nice ring plane and bright Triton..which was pretty close to the planet.
It wasn't sharp and clear and atmospheric seeing was poor - very poor.
Slewing around to the Moon in the west, there was a haze surrounding the quarter Moon...and thru the eyepiece...horrible. A bubbly mess with only quick moments of clarity......just awful.
But it's always fun to explore the terminator and see what's going on. I had noticed some strange very dim banding on the floor of a crater right smack on the terminator...quite odd. I had never seen anything quite like this.
I thought perhaps I was getting some stray lighting bouncing around from the terribly bright alley lights. Switching from a 25mm to a 17mm, the phenomenon was constant and only in that smooth floored crater - not anywhere else.
It got my interest.
Hooking up the Canon Powershot S3, I started to take shots....
It certainly was an odd faint striping on this unidentified crater, so as I waited a few mniutes to shoot another - I tracked down the crater in the meantime...
It seems that it's "Ptolemaeus" - Named after a 2nd century Greek Astronomer mathematician and geographer.
...And it does indeed have a smooth crater floor...so I got it identified. Now, with a personal relationship with the Crater, I followed along with the slightly changing light...
Taking a image every few minutes or so, I could now understand what was going on...the Crater's ragged ridge of mountains were blocking the rising Lunar Sun and causing the light to squeeze through the high reaching peaks.
Quite cool!
Pretty soon, I was viewing sharp peaks stabbing the surface...and rather quickly too...
Remarkable how fast the changes occur, taking into account, Lunar rotation & revolution.
Sky conditions were still very poor and there would be no razor sharp imaging this session, but every so often, the image would steady and I was able to grab a pic...
This was an very interesting session with just me and the every changing Moon this early morning...
As the Moon sank behind a neighbor's roofline...the session was over.
The entire imaging session was about an hour and 1/2 - starting at 11:40 pm and ending at 1:00 am.
This was a good solo session....
