Moonshots

22 April 2021, 19:30 – 21:10 (BST)

This evening the sky was dominated by a bright gibbous moon high up in Leo. The phase was very similar to that described on 23 March, but this time the seeing was even better. I took the opportunity to capture some images, followed by some observing.

Magnifications used: 171x (DeLite 7mm) and 240x (Nagler 5mm). As the Powermate was still attached to my camera, I used the Orion 2x Shorty Barlow with the 5mm Nagler to also reach a magnification of 480x. Copernicus at that power has to be seen to be believed.

Highlights: In addition to all the incredible detail in and around Copernicus, I also resolved four craterlets in Plato. The northern pair are very close together, which I probably why I didn’t split them last time around. I had fleeting glimpses of the Alpine Valley Rille; it appears to be at its widest in (ironically) the narrowest part of the valley, and so can easily be lost in shadow if the illumination isn’t optimal. Hesiodius A was showing well again, as was another concentric crater, the tiny Marth, in nearby Palus Epidemiarum (below). This was a tough one; the interior of the crater was partly shadowed, and I could only see the inner ring intermittently at the highest magnification when the seeing was perfect.

Nature note:

First swift of the year spotted some distance away to the south. (I needed binoculars to confirm it.)

Lunar Detour

14 February 2019, 18:45 – 20:15

A chilly evening after an unseasonably mild day – resulting in the heaviest condensation I've experienced to date, particularly on the secondary mirror. Fortunately, there was only one target tonight - a high, bright gibbous moon.

Seeing was variable with occasional moments of exceptional clarity (a finding backed up by the imaging tests). The moon was dazzlingly bright even at 240x (5mm Nagler) – at least until the condensation set in.

Visually, I saw 3 craterlets in Plato, the centre one clearly resolved.

Rima Birt (adjacent to the Straight Wall) showed up very well despite being some distance from the terminator. (I imaged this with the SP-102, but I don’t think I was ever quite able to see it through the eyepiece.)

Rima Hesiodus was long and very distinctive.

At least one rille was visible inside the rim of Pitatus.

Copernicus of course was the highlight, showing far too much detail to describe here, but the image below gives an idea of what was visible (the eyepiece view occasionally exceeded this).