Lunar eclipse 27 July 2018

Observing conditions during yesterday’s lunar eclipse were excellent here in Gothenburg. Clear blue skies, still 24 degrees C at midnight this extraordinary hot Swedish summer. I decided to observe the eclipse from a hillside in Slottsskogen, the city’s largest park. And I was not alone. Apparently the heads-up for the eclipse had reached many Swedes, and it turned into a social event with people crowding all the park sites with a good view to the southeast.

My observation site on one a hillside facing east. The moon doesn’t show yet but looms in the haze just above the spire at the center of the image.

The moon rose at 21:40 (CEST). Around ten o’clock people around me started to get anxious and I had to reassure them that they hadn’t missed the event, and that they just needed to be patient. As luck had it ISS happened to pass by, which drew some cheers from the crowd and probably stopped some from turning back home.

And then there it was. Occupied pointing it out to everyone I didn’t check the exact time, but around half eleven a very faint dark moon had appeared a couple of degrees above the southeastern horizon. And it soon got better. At eleven the reddish hue of the blood moon was obvious.

Quick sketch made naked eye at 23:00 CEST. Mars is still just under the horizon. The spire can also be seen in the image above and crowns the tower of  Gothenburg Natural History Museum. Behind it is the tower of the Annedal Church (the clock shows 10 in the sketch, but that is due to sloppy sketching).

I had planned to make some sketches with my 7×45 binos, but it was difficult to focus with people moving about, asking questions, borrowing the binos and so on. Below are some of the resulting, quite rough sketches.

Two sketches of the blood moon made when the moon was about to leave earth’s shadow. While sketching the first one it was still very difficult to distinguish any features on the lunar surface, but 20 minutes later the outline of some of the maria could be discerned. The very bright arc marking the beginning of the end was impossible to capture on paper, and was later added in Gimp. Sketches made with 7×50 binos, handheld.
As the eclipse ran it’s course, a very bright Mars joined the show. Some light clouds added to the effect. Sketches made with 7×50 binos, handheld.

All in all this was a memorable evening. The weather was perfect, the moon at it best, and on top of that a cheerful crowd, many of them experiencing a lunar eclipse for the first time.


AR 2565 et al

The solar activity is waning, but the sun still manage to produce some nice spots. Like these ones.

AR 2565 (to the left) and AR 2567. Sketched 18 July 2016, UT 14:00, using a SkyWatcher 10″, masked down to 100 mm, and a Baader Hyperion 17 mm eyepiece (70x). Seeing 4-5/5.
AR 2565 (to the left) and AR 2567. Sketched 20 July 2016, UT 13:10, using a SkyWatcher 10″, masked down to 100 mm, and a Baader Hyperion 17 mm eyepiece (70x). Seeing 3-4/5.

L49: Gruithuisen Delta & Gamma

Sketch made on 22 November 2015, UT 17:00, using a Sky-Watcher 10″ and a TeleVue Nagler zoom 3-6 mm. Seeing improving to 4/5. South is up.

Lunar domes Mons Gruithuisen Delta and Gamma can be found in the moon’s northwestern quadrant, between prominent crater Mairan, and not so prominent Gruithuisen (neither of which are captured in this sketch). The two domes are the features in the center of the sketch, with Gruithuisen Delta to the left and Gruithuisen Gamma, which has been said to resemble an upturned bathtub, to the right.

During the observation my eye was drawn to a small feature just north of Gamma. It actually consists of two small adjacent craters, but with the sun angle at the time of the observation, they looked like one crater Timaoes bridgewith a very thin and shiny white ‘bridge’ traversing the darkness of the crater’s interior. The view was truly mesmerizing, especially as the feature after some time seemed to detach itself from the crater wall. There is of course the infamous O’Neill’s bridge on the western shore of Mare Crisium, and it struck me how easy it is to be fooled by the moon’s ever changing lightning conditions.

The Mercury transit 9 May 2016

I haven’t been able to use my telescopes for a couple of months, but the Mercury transit couldn’t be missed. Back home after work I set up and began observations at 15:00 UT. I was treated with a clear blue sky and acceptable seeing. For the observation I used my trusted 10″ SkyWatcher dobsonian, masked down to 4″, and a 17 mm Baader Hyperion eyepiece (for 70x). I followed the transit for about an hour and a half. By that time the sun had dropped towards the horizon and the seeing deteriorated.

Times as indicated on the sketch. Subtract 2 hours for UT.

Not as impressive as the Venus transit a couple of years ago, I still found the slow progress of Mercury over the face of the sun fascinating to observe. The planet was small, very distinct (of course), and nicely framed by to sunspot groups: AR2542 the larger group at the bottom and AR2543 close to the center of the solar disc. The direction of Mercury’s movement was difficult to pinpoint, and might be a bit off.

I also tried to capture the event with my (handheld) cell phone. Below is the best of several tries.

The Mercury transit captured with a handheld Samsung cellphone.

L 62: Mons Rümker

Rising 1100 meters above the mare in the northwestern part of Oceanus Procellarum are a concentration of lunar domes collectively known as Mons Rümker. The mountain is 70 km in diameter and astronomers have counted 30 domes on it’s slopes.

Observed on 25 October 2015, UT 18:30, using a SkyWatcher 10″ and a TeleVue Nagler 3-6 mm zoom. Seeing 3/5 deteriorating to 2/5. South is up.

Observed at low sun, but with mediocre seeing, I was able to readily discern one of the domes — the central peak in the sketch. Comparing my sketch to the image from Lunar Orbiter 4, inserted below, I seem to have caught traces of at least three additional domes.

Image from the Lunar Orbiter 4 acquired 1967. The image is rotated to match the sketch.

L 36: Grimaldi Basin

At first glance nr 36 on the Lunar 100 list — the Grimaldi Basin — seems to be an easy catch. Its quite big and easy to spot in the lunar landscape. It is even just about visible naked eye. But the basin as such is not enough to tick off L 36 — you need to trace both its “outer and inner rings”, and that is a more demanding task.

Preparing for my observation I consulted a number of maps and images to make sure that I had a pretty good idea of where to look for traces of the rings. Still, and at the telescope, the outer ring was far from obvious. Some parts stood out alright, especially on the eastern side, others were more difficult.

Covering such a large area it took me almost an hour to complete the sketch. Even so some parts were sketched rather haphazardly, and especially the southern parts could have used more attention.

Observed 26 October 2015, UT 19:00, using a SkyWatcher 10″ and a TeleVue Nagler 3-6 zoom eyepiece. Seeing 2-4/5. South is up.

Sunrise over Encke and Maestlin R

One evening last week, while inspecting the terminator, I came across the Encke crater. The illumination was favorable and I decided to give it at go at the sketching pad. Starting out my eyes were soon drawn to a spiky pattern closer to the terminator. I have recently bought a copy of Harold Hill’s wonderful A Portfolio of Lunar Drawings, and I immediately recognized the spikes from one of his drawings  (p. 70-71). I decide to extend the range of the sketch and to try to render both Encke and the shadows cast by the remnants of Maestlin R.

Sketched on 23 October 2015, UT 17:45, using a SkyWatcher 10″ and a TeleVue Nagler 3-6 zoom eyepiece. Seeing 4-5 and with some interference from light clouds. South is up.

Maestlin R draws it’s name from Maestlin, a small and rather unassuming crater just to the north of it (bottom right in sketch). The spikes are created by a series of peaks in the degraded crater wall and cast on the smooth mare. At the time of the sketch the western wall of Maestlin R shone brilliant white, creating a striking contrast.

Encke is a rather large, polygonal and floor-fractured crater. Several ridges were seen on the floor, most notably a ridge traversing the floor from north to south.

Mike Wirth have imaged the area under similar illumination. The image can be found on LPOD.