Thursday, July 11, 2019

moon in 20"

During dusk last night (which lasts until almost 10pm) I had a look at the moon with the 20".  Wow!  I could not believe all the detail visible.  Crater chains, wrinkle ridges, craterlets everywhere, etc.  Used 205x & 333x mono.  Amazing.  The views removed any doubt that installing the 20" was a mistake -- I'll get much use out of its versatility.

Later on I used binoviewers.  My eyes were more relaxed though the field was narrower.  Five Plato craterlets, and the Alpine Rille was easy.  So much greyscale contrast.  Another key view, as I scanned along the outer limb: There was a prominent cone peak, looking like Kilimanjaro -- and the horizon along the other peaks and ridges did not follow an overall curve, but was peaked.  There were two large craters just before the horizon and I bet their impact caused the peaked deformation in the very curve of the crust itself.  I can't find any of this in my atlas...

I also had a look at Jupiter, which was HUGE in the field.  Very easy to see detail.  GRS was a fifth of the way through a passage: it was small, orange red, and was bifurcating the band it rode on.  There was a giant purple festoon in the equatorial area.  At full aperture the moons were disks and showed albedo (first I've noticed that).  With the 8" mask the moons tightened to smaller disks, and the amount of detail was slightly less though I didn't need to wait so long for seeing.

Around 11pm the marine layer moved in.  It will be clear the next few nights so I'm looking forward to more of this.

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