A Very Thin Moon and Mercury

This one will be a challenge. This evening a very thin Moon may be visible just below Mercury as the Sun sets. The Moon will be a mere 1.3% illuminated and only 7° above the horizon at sunset. Mercury may provide a bit of a signpost that can be used to find the Moon. It will be located 2.5° directly above the Moon, shining at 2.8 magnitude. As Mercury is heading for inferior conjunction, it too is a thin crescent. The pair will be 10° south from the point at which the Sun slips below the horizon.

The Moon and Mercury

A very thin Moon will rendezvous with Mercury this evening. The pair will separated by about 8° and at the same elevation, over 20° at sunset. The Moon will be a very thin crescent, only 7% illuminated. A little over 5° north of Mercury will be Pollux, with Castor a bit further north, both stars about a magnitude dimmer than the planet which is currently about zero magnitude.

A Missed Eclipse

Plans for a summit run and some lunar eclipse photography. A midnight alarm clock and departure for the summit was the strategy. I planned to shoot time lapse of the eclipse setting over the Keck telescopes. But the best laid plans sometimes hit a snag…

I had noticed some minor power loss and roughness in the engine heading into work. Some condensation in the system? Perhaps just some bad gas? It was on the way home that the trouble became truly clear. A rhythmic stutter accompanied by a more severe power loss. As I limped home listening to the engine I realized that at least one cylinder of the six was not firing. A faint smell of gas when I got out of the vehicle just seemed to confirm the hypothesis.

That evening I spent a bit poking at the engine, inspecting for a loose connection or some other easy cause. I removed and cleaned the mass air sensor, a known trouble spot. Checked the air intake and ignition system. Removed battery power to allow the electronic engine controls a full reset to default settings. Still, when I started it up there was that rhythmic stutter.

Lunar Eclipse 20070828
Total lunar eclipse of 28 Aug 2007, photo is a 8sec exposure with a Canon 20Da on a 90mm f/12 APO
I was not going eclipse chasing this night. No way was a partially crippled vehicle going to make it to the summit of a 14,000ft mountain.

Instead I simply set the alarm clock for a bit before totality and watched the eclipse from my front lanai. I made no attempt at photography, I do have quite a few decent eclipse photos. Instead I simply watched as the Moon ghosted through a thin layer of clouds. It was quite pretty, a bright Orion and Gemini were visible through an opening for a while. Much of mid totality was lost to the clouds, but it opened up again at the end allowing a nice view of the first touch of direct sunlight on the Moon.

As for the vehicle? I still was not certain what was the issue. This could be the result of something truly serious considering the engine has well over 180,000 miles on it. Plans for a replacement vehicle are under consideration, but I love this old truck. The first new vehicle I had ever owned, a veteran of hot dusty Arizona mining roads, of icy mountain passes, of rocky Hawaiian coastlines carrying scuba gear in the back. How many times has this vehicle waited through the night, telescope setup beside it, while I explored the sky from some remote and dark campsite? A trusted steed that has carried me to so many great places and always gotten me home.

The maintenance manual has a list of a dozen things that can cause misfires. May as well start with the easy (and cheap) stuff. I drove Deb’s car into Waimea to run a few errands and pick up a set of ignition cables and spark plugs.

Damaged Spark Plug Cable
A damaged spark plug cable shows why.
It was the first cable I removed the revealed the trouble, a bad break in the cable where it had rubbed against a mounting bracket for the fuel line. Arced and blackened it was clear that my hunch was correct. A sense of relief, perhaps it was something this simple. I won’t know until I finish the job of replacing all six cables and plugs.

That would be almost two hours later, two hours of cursing the engine designers who would obviously not ever have to replace the plugs on this engine. Who puts a hard fuel line right in line with the spark plugs? I go back to the toolbox for the 3/8″ universal joint and spend a few minutes figuring out what combination of extensions will get me through which gap in the hoses and lines. Really? Is cylinder three’s plug under there? I will have to do it entirely by feel.

Finally! All plugs in place, cables neatly routed around the block, tools picked up from around the engine compartment, I have a chance to turn her over. A quick crank and she starts, idling with a smooth purr that is simply music to my ears. My old friend will be with me for a little longer.

This was the last total lunar eclipse for the next three years. I did watch it, remembering other total lunar eclipses across the years. An eclipse seen from among a stand of saguaro cacti in the Arizona desert, another eclipse watched from the Mauna Kea VIS just a couple years ago. A copper moon high over the broken walls and ruins of a 12th century priory. This eclipse will mark yet another memory, to be recalled when I again sit under a blood red Moon in the middle of the night.

Lunar Halo

Damon alerted us to a nice display of a lunar halo currently gracing the skies over the Big Island. A nice example of a common 22° halo that can occur any time there is a thin layer if high cirrus. The 22° angle from the Moon is a result of refracting moonlight through ice crystals. These high altitude crystals act as little prisms, catching and deflecting the light at specific angles. The halo is actually very large, extending from 22° to 50° away from the Moon, but is brightest at the inner edge.

Lunar Halo
A 22° lunar halo produced by ice crystals high in the atmosphere over Hawai’i on 8 Dec 2008
Halos like this are really quite common, but always seem to catch the attention of those who do not regularly watch the sky. There are many fantastic sights that occur regularly around us, all we have to do is keep an eye to the sky. It has taken centuries to learn how these effects are created though the play of light and water, even now there are some that are poorly explained. It is fascinating to learn what can occur and how it works.

There is a great website, Atmospheric Optics, that has examples and explanations for the many beautiful effects that the play of light can create in the atmosphere. Sun dogs, rainbows, parhelic arcs, glories, specters and more.

This halo is fairly broad and ill defined, probably because the ice crystals are randomly arranged. The halo could be sharper if the crystals were all at the same orientation to us, something that can occur if the winds are right. I attempted a shot of this one, the first time I had attempted to photograph a lunar halo. Not the greatest photo, this was pressing the camera to it’s limit. Even so the image starts to show effects invisible to the human eye, including a hint of color at the inner edge of the halo.

Of Lava Flows and Lunar Eclipses

A good lunar eclipse high in the sky. This was something I have not seen for a while. I have seen several lunar eclipses over the last few years. But they always seemed to be low in the sky from Tucson, rising with the eclipse already in progress. Thus as the date of this eclipse approached I was planning to view it properly. The eclipse would be high in Hawaiian sky, transiting with the Moon in totality. Perfectly placed to view the entire eclipse under the most ideal conditions.

Eclipse Revelry
Everyone at the VIS was enjoying the night!
The timing was highly convenient as I was scheduled to be on the mountain in any case that evening to help prepare for an interferometer run that night. Simply pack the telescope in my vehicle and drive to Hale Pohaku at the beginning of the day so it is waiting with what I need that evening. The scope I chose was my 90mm APO, the focal length was appropriate to frame the Moon well on the Canon 20Da camera. This I mounted on the Losmandy G-11 mount quickly polar aligned with the polar scope and set to track at lunar rate. This particular setup had not been tested together and I thought it would work. I was pleasantly surprised when everything not only worked, but worked quite well.

There was quite the crowd gathered at the Mauna Kea VIS. No surprise, the VIS is the best place on the island to view anything astronomical. Above the clouds and tropical haze the side of Mauna Kea offers a clear view of pristine skies and several telescopes available for anyone to look through. What was surprising was the weather, while the skies are usually clear the VIS can be very cold, and if you add wind the conditions can be miserable. This was not the case! It was cool but not cold and there was no wind beyond a slight breeze.

Eclipse Observing
How to properly observe an eclipse, set the camera on automatic and sit back and enjoy!
We had a couple busloads of high school students, quite a few local folks who knew where to go for an eclipse and the usual group of tourists. The atmosphere was rather festive, a couple musical instruments had appeared and everyone enjoyed the night as the moon slid out of the light.

The proper way to watch the several hours of a lunar eclipse is in comfort. Thinking ahead I brought a lounge chair and setup properly where I could monitor the camera and see the frames on the LCD screen as they came in. This worked perfectly. I could view each frame as it was taken without getting up and adjust settings on the camera simply by reaching over. Between each frame just lay back and enjoy the view.

Well, maybe I am understating the amount of work, things were not that relaxed and the camera took a fair amount of tending. I could not get the camera to autoexpose well with a single bright object in an otherwise black frame. The camera insisted on overexposing the Moon badly, even with automatic bracketing the situation did not work until I just put the camera in manual and adjusted the exposure regularly. The scope did not track perfectly and I did need to adjust the position a few times each hour. But the setup and tending were worth it as the resulting pictures are quite satisfying.

Lava flow from the MKVIS
Lava flowing from the July 21 vent of Kilauea as seen from the Mauna Kea VIS about 30 miles away, taken with the TV-76
This eclipse was darker than any I have seen lately, the Moon dimly seen high in the sky, my camera exposures running to 30 seconds to get a decent image. Once the view of totality had worn off it’s novelty the other telescopes began taking advantage of the truly dark conditions to show deep sky wonders to the crowd. The scopes jumped from Galaxy to globular clusters with the view being fully as good as a moonless night. It seemed of to be looking at M31 and other deep sky objects with the unaided eye on a night of a full moon.

As the eclipse wound down word of another spectacle made its way to me, the glow of something odd seen to the south. This got me out of my comfortable chair to go and see. Surprisingly the usual solid clouds on the east side of the island had parted and the brilliant golden glow of fluid lava was to be seen! There was some confusion as to what it was, some thought it was the lights of Hilo, but there was no confusion to those of us familiar with the view from Hale Pohaku.

The latest lava flow from a rift on the eastern flank of Kilauea was a river 100m wide and several miles long, even from our vantage point thirty miles away we could clearly see the stream. We could see the lava falls near the head of this river with binoculars as well as most of the course. The view of an eruption and an eclipse was and extraordinary reminder of the dynamism of the earth and universe around us.

Above is one of my photos from mid-totality taken with the 90mm APO and a Canon 20Da DSLR, note that several stars frame the moon. Check out a few more pictures of the eclipse from the visitor center by Simona Vaduvescu

Lunar Eclipse 28Aug2007
Total lunar eclipse, photo is a 8sec exposure with a Canon 20Da on a 90mm f/12 APO