Monday I spent the day on the summit, I often choose Mondays, if I have a choice, as we often have a smaller crew and getting access to the various parts of the telescope is easier. There are fewer people trying to do fewer things at once. Monday turned out to be very good choice indeed, the first clear day at the summit since Christmas. We arrived at the summit to deep blue skies over a landscape of white. Poli’ahu has again blessed the summit of the White Mountain with deep snow.
Looking across at the Keck 1 dome from the top of Keck 2 with Mauna Loa in the backgroundA small crew does have a disadvantage as well, the chance of being drafted into whatever job needs being done. Not that I was unwilling, the job in this case was clearing snow and ice from the domes. This meant climbing to the top, one place in the facility I had not yet had a chance to go.
So after rigging myself in full safety harness I climbed the dome with the crew. The view from the top is stunning! A full 360 degree view of the summit on a perfectly clear sunny day. The entire summit is blanketed in a beautiful white coat of snow, one of the most dramatic scenes I have ever witnessed. The small Canon G9 camera fit in a breast pocket, small enough not to interfere. I began filling my memory card with many images of the view from the top, reveling in the spectacular vista.
Mike Dahler clearing snow from the edge of the Keck 2 shutterNot that it was all sightseeing, there was work to do, shoveling snow and chipping ice from the areas where it could interfere with operation of the telescope. Ice and snow coated the upper sections of the dome. Several inches of ice needed to be hammered free of the steelwork and drifts of snow, up to two meters (six feet) deep were packed into any corner and along the side of the shutter. Blocks of ice and shovelfuls of snow flew, crashing to the ground 30m (100ft) below. A crew worked each side of both domes for several hours to complete the task, made all that more difficult by the extreme altitude.
In the thin air there is only so much you can do before you are short of breath. Put down the shovel for a few moments and take a few more pictures. I have material from which to assemble a full panorama as well as dozens of individual images.
After much of the snow and ice had been cleared by hand there was one more step to accomplish. Clear the large drift of snow from the back of the shutter by using the shutter itself as a snowplow. This drift is many tons of snow, over 2m (6ft) thick at the top and about 12m (40ft) wide. When it came down it becomes an artificial avalanche, with huge blocks of snow falling to the ground far below.
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.
A 22° lunar halo produced by ice crystals high in the atmosphere over Hawai’i on 8 Dec 2008Halos 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.
Monday morning comes with a round of meetings. The entire department sitting down to plan activities for the week. In about ten minutes I need to set up for a technical presentation, my Power Point file on the thumb drive beside a pad of paper. It is just past the opening niceties that my cell phone rings, an abrupt interruption that stops all conversation around the table. It takes a few seconds to fumble the phone out of the belt pouch, stabbing the button on the side to silence the cheerful and yet unwelcome tune.
Looking at the number on the little screen I take a deep breath, reading no further than the area code before all thoughts of the meeting fade. This is the morning my father is in surgery, a heart bypass operation. It is not his first, the family went through this same event many years ago, but he is older, a worry is there, coloring all emotions. The last times I have seen my father he has seemed to tire a little more easily, looked a little older. Unable to join my mother and I in a swim out to the reef, turning around part way out to sit on the beach instead. Opting not to travel to the summit and the thin air of 13,600ft for a tour of the telescope where I work.
Fredrick Cooper kayaking in Warm Springs Bay, Baranof Island, AlaskaWe are planning another vacation to Alaska this coming summer. A trip that will bring together close family who are normally spread across half a continent and more. Twenty two days on a rented boat out of Juneau, fishing, cruising and watching bears, glaciers and whales. But most importantly spending time with my family, something I all too seldom do. Chasing dreams and working at the observatory in Hawai’i has a price, years spent far from family.
For a few seconds after the phone is silenced I can do nothing but stare at the number. I need to return this call, but am loath to do so. Sliding out of the conference room I feel my co-workers’s eyes following. Once in the hall I take a breath and attempt to remember the keys needed to redial the last caller. For a moment the sequence escapes me, my mind far beyond the keypad. I hit end to reset the phone and start again.
The phone rings, and continues to ring, I hold my breath as it takes far too long for someone to answer. Finally I hear my mother’s voice, a smooth and normal tone that puts fears to rest even before her words have meaning. The news is good, everything went well, he is in recovery and should be be receiving guests shortly. I return to the meeting, making my apologies, turn on the projector and begin to load the file into the laptop.
There is a boat and a fishing pole waiting in Alaska this summer, I will be there.
The sunset view from the summit of Mauna Kea is truly spectacular. From the summit you are usually above the clouds, watching the sun sink into a cloud layer thousands of feet below. The colors are intense, the deep blue sky, the red cinder and the gleaming telescope domes. This spectacle draws tourists from across the globe, trekking up the mountain just in time to witness sunset.
The shadow of Mauna Kea rising through the haze at sunset with the pink of the Belt of Venus aboveOne part of this spectacle is the enigmatic shadow that rises through the eastern haze, a beautiful pyramid of darkness that stretches to the distant horizon. A serene and yet awesome sight, the shadow reaches for infinity through the pastel shades of the Belt of Venus above the blue-grey shadow of the Earth itself. The shape is a perfect pyramid, with a symmetry not expected in a natural phenomena.
Oddly enough, it seems that the actual shape of the mountain is not that important in the creation of such a triangular shadow. The shadow will show that beautiful shape regardless of the mountain’s profile. Even a flat topped mountain will have a shadow that converges to a point at the top. This contradicts our experience, where common shadows match the shape of the casting object. We expect a shadow to portray the object.
A mountain shadow is different, the shadow is elongated to a great distance by the scales involved, in this situation the geometry dictates a different result. The secret to the shape of the shadow is that it is driven by the effects of perspective, with the shadow reaching to a vanishing point in the far distance. In 1979 the problem of the mountain shadow shape was mathematically modeled by William Livingston and David Lynch. They showed that regardless of the mountain’s profile a conical shadow would be perceived by a viewer near the summit. The proportions may differ depending on the profile of the mountain, but the conical shape would remain.
In the case of Mauna Kea, the effect is not obvious, the mountain does have a fairly symmetrical shape with steep sides. A viewer might not recognize the fact that the projected shadow does not match the shape of the volcano. An astute observer may notice a discrepancy, Mauna Kea is notably rounded at the summit, yet the shadow possesses a sharp apex.
I was completely unaware of this until it was pointed out to me a few days ago by Dean Ketelsen when I posted the Mauna Kea mountain shadow image. I suspect Dean has had many opportunities to see this phenomena from atop Kitt Peak, a flat topped mountain that casts a conical shadow.
At the Mauna Kea Visitor Information Station telescopes are available every clear night for the public to enjoy the wonders of the night sky. Every evening a set of telescopes ranging from 102mm to 16 inches is setup in the patio beside the VIS. The gear is used heavily, every night of the year, the wear on the telescopes does exact a toll. The abuse is constant, kids hanging on the eyepiece, volunteer operators who have never used a telescope, rain, fog, blowing cinder dust. Conditions that were never foreseen by the designers and far beyond what most telescopes encounter. Sometimes the condition of the equipment is embarrassing, dirty eyepieces, groaning mounts that refuse to track, much of the gear just looks worn and tired.
An 8" telescope mirror covered with a ridiculous amount of dustIt is hard for me to see this, but at least I can do something about it, I do, after all, fix telescopes for a living. It is not unusual for me to spend an evening repairing a telescope and I have made a point of getting some more extensive maintenance accomplished.
My first effort last year was to clean and repair the small dobsonians used by visitors every night. Two eight inch, a six and a 4.5″ Orion dob are put out for anyone to use, from adults to children. After years of use they were in horrible shape, bearings and focusers were coming apart, collimation gone, moisture dissolving the woodwork, a finder attached with duct tape, the mirrors so covered with dust it is surprising there was much of an image to see. One of the eight inch scopes and the 4.5 inch were in pieces in the warehouse after a fix attempt by another volunteer. It took a few days of work to put all to right. Stealing parts from an older scope, repairing what could be saved, cleaning and pounding out a couple dents. Clean, re-install and re-collimate the optics. Four dobs back in service and in better shape than they had been in quite some time.
Parts of a Losmandy G-11 telescope mount spread across a table topThe 16″ Meade LX200 should be the flagship of the equipment used at the VIS. But for all too long it refused to work properly, it would not track. A trip back to the manufacturer failed to correct the problem, despite nearly a thousand dollars in shipping fees for factory service the telescope still would not work most of the time. Most volunteers would not use it, having given up in frustration. Surprisingly the issue was obvious, just listening to the scope indicated gears not fully meshed and grinding on one another. An hour’s worth of dismounting the scope, opening the bottom panel and re-seating a motor mount had the telescope back on sky and slewing from target to target. The scope has failed since, but the problem was even simpler, a loose connection found after a half hour of poking around.
Currently, one of the three Losmandy G-11 mounts belonging to the VIS is in my garage, spread across the table in many parts. I spent a few hours yesterday dismantling the mount and cleaning the grease and cinder dust out of the bearings. It is in pretty good shape, a good cleaning, re-seat the worm gears and some new clutch pads and it will be ready for a few more years of service. I need to get some more grease before I can reassemble the mount, but otherwise everything is ready to put back together. Finish this one and there are two more like it in sore need of maintenance.
One thing at a time, of course by the time I get through it all it will be necessary to start over again…
I enjoyed moonrise tonight on the way home, and then enjoyed it again. The first was just after leaving Waimea, a golden full Moon rose over a band of clouds, a beautiful sight as I drove home from work. My drive then takes me deep into the shadow of Mauna Kea, the Moon disappearing behind the bulk of the mountain. A second moonrise found me about ten miles further down the road, with that golden orb rising over the summit. Two beautiful moonrises to grace the end of a long day.
Venus was visible in the golden glow of sunset, mercury right below if you knew to look for it. I saw no sign of Saturn which should have been a ways below the other two, it was probably hidden by a band of clouds that occupied the right spot.
Yes, I did say I was driving home from work on a Saturday. One of the guys on the crew is out with a bad back, and I worked a couple more days on the summit to cover. I was performing some procedures I had never done before, optical alignments in preparation for using the interferometer that night. As a result I will have spent five out of seven days on the summit, quite a bit more than my usual two days a week. I get a day off tomorrow, then back at it Monday. Even tomorrow will not be completely a day off, with an interferometer run in progress there will be some work I need to do from home to check the systems and insure they are ready for the night.
Hopefully the phone stays silent through the night.
There is an article on the TMT in yesterdays’s Honolulu Advertiser. While the article shows growing community awareness of the Thirty Meter Telescope project and puts forth some of the basics, it concentrates on some of the political issues. Those are, as typical for Hawai’i, rather fractious, showing the very polarized nature of political discourse in the state.
An overhead view of the proposed Thirty Meter Telescope, credit TMT Observatory CorporationIt is the comments that make the most interesting reading. These show the wide range of feelings in the community. There also seems to be a misunderstanding about the roles of large telescopes in general. The last two decades has seen an enormous advance in our understanding of the universe and its history. We now know the age of the universe, we have discovered planets around other stars, we have learned that ordinary matter makes up only a small fraction of the universe. These represent huge leaps in our understanding and these revelations have come, to the greater degree, from ground based astronomy. Many of these discoveries have been made, or greatly assisted, by the telescopes atop Mauna Kea.
One of the themes that popped up in the comments several times was the idea that space telescopes are where to put the money and the belief that ground telescopes were “obsolete’, thus projects like TMT are not needed. This could not be further from the truth. Yes there are advantages to space telescopes with respect to interference from the atmosphere. But space telescopes face several severe and inherent disadvantages.
There are many hazards in driving the legendary Saddle Road… bad pavement, regular fog, blind curves and hills, one lane bridges, and do not forget the low flying turkeys.
It came out of nowhere, coming across the road at the very worst time as we rounded a sharp curve with no chance to take evasive action before it struck. My wife saw it first, giving that peculiar short half scream I have long ago associated with impending disaster. We were lucky and it didn’t come through the windscreen as it very well might have. A full grown turkey is a big bird, I suspect large enough to smash right through the safety glass and into the face of the driver and passenger. Instead it struck the pillar on the driver’s side and my side view mirror.
Other that my wife’s shocked nerves the only damage is a completely smashed side view mirror and a dent in the molding. What damage the turkey suffered is unknown as it disappeared, apparently still mobile and able to flee the scene of the accident.
So I will be spending a little time on the phone, calling around to junkyards to see if anyone has a side view mirror for a Ford Explorer and reminding myself it could have been much worse.
Damage to the side view mirror resulting from a turkey collision on Saddle Road, 30 May 2008
How bright a laser beam is needed to allow good public presentations and a good astronomy education experience? In the United States legal green lasers are limited to 5 milliwatts (mW) by the Food and Drug Administration. Many of the lasers sold as 5mW are actually 3-4mW as it is necessary to stay below that limit if you wish to import the laser into the United States or to sell the laser across state lines. 5mW units are fine if you are under fully dark skies, but often you are not, there are city lights, or moonlight and the 5mW beam ceases to be usably visible. This is worse if you are working with a larger group and the distance from the presenter is larger, also making the beam less visible. In practice I have found a beam in the 20-30mW range is about ideal. These lasers are available from a number of sources for around $100. Good visibility in moonlight, good visibility in light polluted surroundings and good large group utility. But importantly, not powerful enough to be truly dangerous.
Deb pointing out the star βPhoenicis to VIS volunteer Joe McDonoughWhere does the 5mW limit come from? The FDA, being a very conservative organization, set the safety threshold at 5mW based on animal and human studies and medical injury data. The 5mW limit is a national standard and applies to interstate or customs transactions, not all states have adopted it. Hawai’i does not appear to have strict laws regarding lasers, licensing or use, so my 30mW unit is legal. This contrasts with my previous home in Arizona, which is more typical of many states. The use of a class IIIb device was subject to licensing, training requirements, and yearly fees. The agency responsible being the Arizona nuclear regulatory office. Sheer bureaucratic overkill that made it practically impossible to legally use a device in the power range I needed, just a few milliwatts over the limit. I am always surprised there is no intermediate class, that a 20-30mW device is classed with devices of up to half a watt, devices that are quite dangerous.
How do I come up with the 20-30mW number as being relatively safe? Being an engineer I understand safety margins and over specification and figured there must be a compromise. The trick was to find undistorted data, without the bias of overcautious bureaucrats. The data is out there on the web, but took some digging to find, many medical journal articles are hidden behind subscription services. Fortunately there are sources like PubMed that are freely and publicly accessible. Eventually I found and read several very informative papers on lasers and eye damage, looked at pictures of laser damage on monkey retinas and looked a damage done by visible lasers in the same sort of power class as those available for public work. I was surprised by actual human damage studies, done on patients who were having eyes removed due to conditions like cancer, where the researcher could do damage without harming the patient. What I was looking for was just what level of laser radiation is dangerous in practical use.
Green lasers in use at the Mauna Kea VIS nightly observing with the Milky Way high overheadThe conclusion I came to was that a 20-30mW unit could cause damage, but was not excessively risky. The data in the papers showed you could generate damage to a retina with even a 5mW device given a long (60s) exposure. But there were a lot of caveats, the beam had to be well focused, the eye could not be moving and it had to be focused for a substantial length of time. In reality a number of things protect the human eye, the first is the fact that the eye is constantly moving, this spreads the power over more than one spot, not allowing cumulative damage at one site. The second is that a bright visible laser will initiate a blink reflex, keeping any exposure in the tens of milliseconds time scale. To prevent these protective effects the tests in the references were sometimes done with anesthetized subjects. At the 100mW power level damage occurred with very short exposures and was quite dramatic.
A 20-30mW laser needs to be treated with respect as injury is possible, but no more than any other dangerous tool we use every day. In practice damage with a laser at a sensible power level (20-30mW) would require prolonged exposure (>0.5sec) on a single site on the retina, requiring staring into the beam. The bright green light would elicit both a blink response and an aversion of the head and eye, particularly in a visually dark adapted environment. I would strongly discourage use of any laser 50mW or greater for public astronomy work. Some of the references showed significant damage inflicted with 50mW lasers and sub second exposures. Lasers at all power levels should be kept out of the hands of anyone too young to understand the implications of the danger posed by a laser.
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.
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.
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 flowing from the July 21 vent of Kilauea as seen from the Mauna Kea VIS about 30 miles away, taken with the TV-76This 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
Total lunar eclipse, photo is a 8sec exposure with a Canon 20Da on a 90mm f/12 APO
