Planet secrets

Nowadays there is a constant effort to find planets orbiting around stars other than our sun. This effort is tied to try and find indications and traces of life, such as we know it. 

We are conducting the same activity on many of our solar planets, some of which we have, and are being explored by probes and satellites sent by us from Earth. So far, we cannot say that we have found any life as we know it, or traces of it. To pursue such efforts, in my opinion, is typical human. We have a tribal  bent.

Another approach we, as humans do, is to theorize, and to make the first efforts to settle on one of our solar planets, or one of its moons. I've written about this about a year ago. There seem to exist surprising and unexpected conditions on the solar planets and/or their moons.

To settle on another planet or moon requires knowing the conditions where you could suitably land and could stay.  There are a number of unexpected and surprising conditions and even movements. Enceladus, Mars, Pluto, Jupiter's Galileyan moons, are all exhibiting some unexpected responses to probes of various kind.

Right now I am reading (slowly) an interesting book about just the topics referred to above. The author is Paul Murdin, published by Pegasus Books, New York, London. The title is THE SECRET LIVES OF PLANETS, the subtitle is Order, Chaos, and Uniqueness in the Solar System. It was a ChristmasPresent to me. The price label was left on the wrapper, the price is very reasonable.

The planets farther away from the Sun may present environments which may unexpectedly be totally strange to us. If we settle long enough on one of  our sun's planet's moons, we may be making a decision to permanently be removed from Earth, and to be forever incapable of physically ever returning "home". 

For myself, I'd prefer to forego any opportunity to travel to anywhere in space. I like it here on earth, with my family and friends. My explorations of space are based on the use of telescopes. 

As an aside, if you begin astronomical efforts, use binoculars for looking at the sky. Binoculars can be generally found in a home. Read my article "Visual Aid" which I published on March 29, 2019 here. You'll probably agree that binoculars are quite versatile, i.e. birdwatching, distance viewing, navigational help when on a ship or boat, and definitly the sky on a clear night.

Little problems

 

Living in an area subject to a lot of cloudy weather, I use my telescopes sporadically. The Christmas and New Years' periods additionally result in family and friends getting together. That means that some clear sky conditions are also bypassed. Because of several days being available, I had time in which I could, and did, check the operation and possible problems on my EQ type telescope mounts and my telescopes. 

From my previous blogposts you'll know that I much enjoy the public astronomy nights which SFU runs on clear Friday nights. I've been using my 3" refractor most often for our RASC participation. The telescope is not heavy and can be put onto the telescope mount quickly. As well, it is easy to align with the celestial North Pole. The reason, of course, is the automatic tracking of any object being observed by moving the telescope westward at the same rate as the Earth's rotation eastward.

The EQ4 tracking mount I use for the 3" refractor has somewhat of an issue though. No matter how closely I align the telescope with North, the object in the telescope's field of view slowly drifts out of view. It's easy enough to correct this by using the control buttons on the Dual Axis Motor Drive which powers both the Right Ascension and Declination motors. However, it requires my periodic attention to make sure that our public guests will actually see the target to which I pointed the telescope.

There are many cloudy days and nights at this time of year. I set up the telescope and mount in our recroom at home to move through a 24 hour tracking run. The idea was to set the time and direction scales on the mount to a start point (I pointed the E marker on the telescope RA axis to the 0 hour mark on the time scale) and to read the scales at the end of the run, 24 hours (actually 23 hours, 56 minutes, and 4 seconds) later. At that point I would have expected to see the E marker to point again at the 0 hours mark. Lo and behold, it pointed instead to 2h and 50 min beyond the 0 mark. This means that the telescope actually indicated that it moved past the 0 hour time marker; it incorrectly showed that it had moved a total of 26 hours and 50 minutes. The tracking motion of the mount is therefore 11% faster than the daily sky motion. Since the Earth turns 15 degrees per hour this result moves the telescope to a position almost 45 degrees ahead of  the position it should have after 24 hours tracking, Instead of moving through 360 degrees, it moved almost 405. I had noticed smaller overruns on other days, even on much shorter test runs. This is what actually made me run the 24 hour test.

My motor drive unit has 4 control buttons to speed up the RA and DEC stepper motors 2, 4, or 8 times by means of a separate speed switch. Each button is dedicated to one particular direction. The RA motor is controlled by an East button and a West button, the DEC motor by a North and a South button. The East button can be used to compensate for the 11% excess tracking speed, but it requires me to push and hold the button to move the telescope back to the observed target. It is a very basic and very slow slewing system - it would take many minutes to move from Vega to Deneb for example. As it exists, this whole system is not suitable for long-exposure astrophotography, in my opinion. It's ok for visual observation and possibly photography of the Sun or the Moon.

The dual axis motor drive

proposed astable  timer (below)

Now the question: what causes this? I was thinking about the gear ratios in the RA motor, or in the mount, the clock frequency in the electronics of the Dual Axis motor drive unit, the pulse rate applied to the RA motor stepper windings, searched for an adjustment capability in the electronics board (found none), and other electronic possibilities. I also searched the internet for electronic schematics (there are dozens) but did not find the one which exactly matched the Dual Axis motor drive above. 

I'm thinking of putting together an astable timer based on the 555 precision timer chip. Its output voltage could control the power provided to the motor drive, i.e. shut off power 11% of the time. That way, the movement of the sky could catch up with my faster-moving telescope. It's a crude approach, but in my working days I built many similar timers to control printers, vending machines, debit card readers, and other equipment. I found the timer shown above in one of my "junk"drawers which contain all manner of parts, most of which are decades old. The shown timer is an unused piece I started about thirty years ago, and never finished. I'll check it out and may modify it to counteract the tracking error. 

Stay tuned. .

Serendipitous Eclipse

It happens very seldom that the weather gives us a break exactly when we astronomical observers want one. Usually it's the reverse: the weather is reasonable just before an interesting event. Then,  just a few hours before event time the weather clouds up, or rain starts, or snow, or any other condition which prevents us from observing is going to occur.

This time, we got a lucky break. The weather cleared up just a few hours before the recent total lunar eclipse. Our granddaughters, who are also members of the RASC (as I am), took some nice pictures of the eclipse (I set up a telescope on the rear porch at home and just observed by eye, binoculars, and the telescope). I downloaded only one image from Slooh. com the remotely-accessed organization.

Here is my only image, taken with a remote-control telescope at Slooh.com:

I'm always fascinated by the media's statements when they are hyping a completely normal astronomical event which repeats itself often with descriptions like "Blue Moon, Harvest Moon, Wolf Moon, Super Moon", and other mystical names.

We will have no more total lunar eclipses this year. A partial lunar eclipse this year will occur on July 16. The next total lunar eclipse will occur on May 26, 2021. On November 19, 1921 will be a partial lunar eclipse. Another total lunar eclipse occurs on May 16, 2022. In between occur several penumbral lunar eclipses, on Jan 10, 2020, June 05, 2020, July 05, 2020, Nov 30, 2020 all usually almost invisible, because the brightness of the full moon varies very little. Penumbral lunar eclipses are caused by the Moon just missing the Earth's shadow.

The Moon's orbital plane differs from the Earth's orbital plane around the Sun by about 5 degrees. There are two crossover points, the ascending and descending nodes. Both solar and lunar eclipses (partial and total) can occur only when these nodes are "in line" with the Sun, and the Moon is very near, or at one of them. That also means the both types of eclipses occur at either "new Moon" (solar) or "full" Moon (lunar). These nodes slowly move around the plane of the Earth's orbit, giving rise to various series of "eclipse cycles" which repeat over hundreds of years.

You can let your imagination play by thinking about what these various types of eclipses would look like if you found yourself on the Moon...

The total lunar eclipse on January 20 was indeed serendipitous.

Getting to know the sky

At our public star parties a number of people have never seen the impressive objects we usually show through a telescope ask about how, and at what cost they could acquire a telescope to look at the stars, planets, the Moon, and other objects in the sky.

My long-time come-back to this question for people who are new to looking at the sky through one of our members' or SFU's Trottier observatory's telescopes are questions of my own. I ask whether they own a pair of binoculars. If the answer is yes, then the my next question is: have you ever looked at stars through them? Many people have never even thought of doing this. To those people who have done it, I put this question: would you know where to look for the Andromeda galaxy (or some other object in the sky)? The answer many times is "no".

With the apps available on computers, tablets, smartphones, etc., many people compare the sky portrayed on these devices with the sky visible at the time. That's a legitimate approach, but, in my opinion, if one comes to rely on these devices, one usually does not "learn" the sky.

I grew up at a time when these devices were "science fiction". Having had an interest in astronomy since I was eight years old, knowing the sky is an "innate" feeling for me, at least as far as the northern hemisphere is concerned. I've not much time closer to the equator, therefore I don't have the same familiarity with the southern sky.

In my younger years I did some serious astronomy, for instance submitting observations to the AAVSO (American Association of Variable Star Observers) regarding variable stars, Zürich sunspot numbers, occultation timing, and other things. These activities, and many others are now done by both amateur and professional astronomers (the two categories really overlap nowadays, since the technologies available are now highly sophisticated and not very expensive), and generate very precise and detailed results.

At this time in my life, my greatest enjoyment comes from our public star parties. I get a kick out of comments like "wow", "cool", "amazing" when people are looking through one of my telescopes at the sky. In particular, I feel very happy when a young person comes up with these comments.

Adults who are "newly exposed" are equally amazed. The objects which usually are the source of this are the "jewels" of the sky: Venus and its phases, Jupiter and its moons, Saturn's rings, our Moon's craters, open and globular star clusters, etc.

Here are the recommendations I usually make:

(1) When outdoors, preferably under a dark sky, use only your eyes to get to know the sky and constellations using one of the star finders we hand out freely on various occasions, or find a printed or on-line star atlas. Familiarize yourself with the constellations and their annual positions at various times of the year. Dig deeper, and become knowledgeable about the Earth's orbit and how that relates to these times of visibility. Try to find objects which our unaided eyes can readily perceive (Pleiades, Hyades, Milky Way, compact constellations, etc.). If you feel that you'd like to see these targets in more detail, then

(2) use your binoculars to find these objects. If you are a young person, 7x50 binoculars are ideal. Your age and personal preferences have an effect on what may be your perfect binoculars. Almost all binoculars will show far more detail in the night sky than the "naked" human eye. Using binoculars will "train" you to find sky objects. At first you may spend some time to succeed, but you quite quickly become better at it.

Many very descriptive dissertations have been written about the use of binoculars in astronomy. Even advanced astronomers, at least those who are involved in the visual observing, have their favorite binoculars on hand when observing. Personally, when I'm setting up one of my telescopes, I always have binoculars with me. They are very helpful in locating objects for which I want to use the telescope. Once you have become familiar with their use and characteristics, and if you are looking for even more detail, a telescope may be your next "step up".

(3) Before you buy a telescope, understand the basic requirements. Beside the size of your contemplated purchase, understand differences between the various types. This is a much-discussed and written-about subject. The best way to find out is to attend star parties, such as the ones run by the RASC, or SFU's Trottier Observatory, because you will usually meet people who are using different types of telescopes. You will also become aware of the fact that purchasing a telescope entails having to buy a sturdy, and accurately manufactured telescope mount. The best telescope is next to useless unless it can be held steady, and does not shake with every little breeze. The matching of telescope to its support is another important topic.

Computerized telescopes are a helpful addition to the range of telescopes available. Again, unless you have learned how to find objects in the sky as described in (1), (2), and (3), you likely won't get to know the sky in the detail necessary. Getting to know the sky "in depth" is best done by learning to point a telescope "manually".

If you become a member of the RASC, you'll have access to many benefits. As a member, you can borrow one of the RASC's library books, and/or a loaner telescope for a limited time. You also receive several publications, chief of which is the RASC's annually published Observers' Handbook. It contains a wealth of data, among which you'll find detailed information about binoculars, telescopes, human eyes, and upcoming monthly events (eclipses, occultations, planetary positions - a plethora of facts and discoveries). The Handbook is used by professional and amateur astronomers world-wide. The RASC also owns the magazine "Skynews", and publishes the RASC Bulletin and local RASC centre newsletters. All these are included in the membership.

Try it - I think you'll like it.

Blue, blood, and "Supermoon" eclipse

On January 31, 2017 morning, I got up to have a look at, and take some pictures of the total lunar eclipse which has been hyped as the "blue, blood, eclipsed Super Moon". As the weather gods would have it, there were variably transparent clouds everywhere. I took a total of 356 pictures, many of which were of poor quality because of this. To control the camera, which was attached to a tracking mount, I used my 27" iMac, loaded the Canon EOS control program, and connected the camera to one of the computers USB ports. The program allows remote control of various camera functions, including exposure and ISO ratings.

I set up the Canon 60Da camera at the window inside my office. This window is on the west side of our house and fortuitously looks out on that part of the sky in which the eclipse took place. An old Pentax 200mm and a 2x Barlow lens (both Pentax threads) resulted in an effective 400mm telephoto lens; this combination was attached to the 60Da by means of Pentax-thread-to-Canon adapter. In order to get reasonable quality images, I opened the office window, and took out the mosquito screen. That meant that the office got really cold; when daylight arrived there was frost on the roof of houses and frosty cars. To make this 5-hour photo session more comfortable, I set up my MacBook Pro laptop, using VNC, to communicate with the iMac in the office over my internal computer network. VNC was set to show and control the iMac screen in the office. I set up the MacBook in the kitchen to keep warm and kept the office door closed.

Here is a picture taken near the beginning of the eclipse:

The Moon at the beginning of the eclipse (with clouds - image cropped from a wider original)

The cloud situation was variable throughout the whole eclipse. This meant that I had to experiment continuously with exposure times and ISO settings (the reason why I took so many images). But whenever I hit the correct exposure, I could suppress the clouds and bring out the actual image of the eclipsed moon. This image was taken under those conditions:

The partial phase - the bright part is highly overexposed in order to bring out the colour inside the Earth's shadow. This colour of the shaded part is caused by the Earth's atmosphere refracting the Sun's light into the shaded part. If you were on that (shaded) part of the Moon, the Sun would be covered by the Earth, but Earth would be surrounded by a red "sunset" ring.

This is an image of the Moon at mid-eclipse through a fortuitous, short "clear" hole in the clouds:
 

The Moon at maximum eclipse.  It is illuminated by the Earth's atmosphere's refracted sunlight light only.

The cloud situation got worse after the eclipse total phase was finished. The Moon was also much lower in the west. Here's another through a "cloudhole" shot. It was the last clear one:

Partial phase past totality.

The final image below. A thick bank of clouds rolled in and covered the Moon completely. The variable clouds earlier fortunately occurred in the right time frame to see most of the eclipse.

"Good bye". The thick black cloud bank spelled eclipse end for me.

Eclipse!

To show today's partial solar eclipse (it was not total here) to the public, several of us - members of the Vancouver Centre of the Royal Astronomical Society of Canada (RASC) - set up solar and "white light" filtered telescopes at Telus Science World here in Vancouver. We also gave out hand-held eclipse viewers - we had a limited number, and have none left now.

The eclipse had been advertised extensively world-wide. Telus Science World (and we) anticipated a large crowd, and that certainly was the case. People queued up more than hour before the beginning of the eclipse. The line-up at each of our telescopes was in the hundreds all through the eclipse; someone mentioned that a total of about ten thousand people were in attendance inside Science World and at our telescopes. It was a grand occasion. We have had similar reactions at other events (though not the huge crowds of today). I think it shows that, when it comes to finding things out about what goes on in space, people have an innate interest.

At the time near maximum of the partial eclipse, when the sun was only a crescent reminscent of a young or old Moon, the sunlight turned into an unusual bluish/gray colour and was noticeably fainter. A drop in temperature was also felt by most people. It is odd to see faint sunlight under an absolutely clear sky. It was not like sunset or sunrise - those are commonly red.

This was a very successful event; perhaps we have steered a few young people in the crowds to study and get involved with working in astronomy, and/or related sciences. There is really no boundary between any of the sciences; STEM technologies underly most of them, particularly astronomy and space travel.

Why don't we order up another eclipse soon, we all had a great and fun time.

Catch up

Since my last post in April, we spent almost the entire month of May in California. Before our trip there, my wife and I spent the day of May 3 in memory of our son Derek, who died on that day in 2011. That day will never be a happy one for us.

A couple of days later we took the car to get to San Diego, with a stop along the way to visit a good friend in Chico, California. We also happened to stay a couple of nights at a Hilton-Hotel-affiliated place called Homewood Suites. We found them to be very "user-friendly", with courteous and efficient staff, and breakfast and happy hour included in the very reasonable price of the rooms.

Our San Diego stay was with friends we've known for almost 40 years, and whose house is almost like a second home to us - we've stayed there so often. By chance, we arrived at the time when the host's nephew and a home-town friend (both of whom live in Germany and who are also our friends) were also staying at the house. These two left a couple of days after we arrived, but we had a chance to get up-to-date.

Our host is dealing with some age-related medical issues; we had come to help keep an eye on him during the time that his wife attended a family reunion in Germany. There are always local friends and neighbours dropping in too, so our time there was never boring; we've gotten to know most of these people during the years we have visited there.

On the way back, we stopped for the first night in Fresno, the next in Medford, and spent a couple of hours at Crater Lake, where we had deposited a small part of our son's ashes two years ago, following the wishes he had first expressed in 2007 (http://www.penmachine.com/2007/07/my-favourite-places-and-when-to-take-me). The day was cold (4 degrees C), but sunny. There was still an appreciable amount of snow, and the road around Crater Lake was only partially open.

Here are a couple of pictures:

Crater Lake (taken from the air April 2016)

We dispersed some of Derek's ashes here in June 2014.

We left Crater Lake around noon and drove north on highway 97 to Madras, Oregon. This is one of the places almost exactly on the centre line of the path of the August 2017 total solar eclipse. It will be the first total solar eclipse in North America since 1979. As expected, all the hotels in Madras are already fully booked for the eclipse, but the area around the city is quite flat, so the eclipse path (which is a couple of hundred kilometres wide) is accessible in a wider area. Google "Solar eclipse 2017" and you'll get all kinds of information links.

The solar eclipse pictures I took on February 26, 1979 (in Winnipeg - the "diamond ring" picture was taken by Neil Laffra on Hecla Island in Lake Winnipeg). At the time I had a complete darkroom in our basement where I developed the film and prints, and mounted them as shown. They have been hanging on our wall since then.

We spent our last night in Portland, Oregon, and, after battling the always busy traffic in Seattle, got home at a reasonable hour.

Since then, I have been active with my astronomical endeavours, meetings, and Royal Astronomical Society of Canada Vancouver Centre public events. The most recent was the celebration of Canada Day in Haney (unfortunately, not a sunny day). However, our various telescopes served as exhibits for the several hundred people who stopped by for a look through some of the telescopes and the free informational handouts.

Canada Day with the RASC

(one of the rare instances when no people blocked the view)

Eclipse wipe-out

The Moon went through a total eclipse this morning (from 3:25 am to 4:24 am PDT). Before totality, as the the Moon moves into and out of the Earth's shadow, it goes through a number of stages.

The magazine "Sky and Telescope" published a very descriptive illustration of the process:

I had decided a couple of days earlier that I'd try to photograph this event. On our back porch, I set up a Canon 60Da camera with a 500mm telephoto lens on an iOptron SkyTracker mount (to compensate for the Earth's rotation during that event). The camera can be controlled via our home computer network; I'm a creature of comfort and did not want to sit out in the cool night. Instead, I watched the process on my desktop computer and took pictures as things progressed. All evening, the sky was covered with thin clouds, but the Moon was visible through them.

Here's what that looked like:

As the time for the eclipse approached, the clouds turned more variable, so camera exposure times had to vary with the varying transparency of the clouds. Alas, just as the time for the beginning of the "total" phase approached, the clouds got so thick that the Moon could not be seen and the sky stayed that way until late this afternoon.

The penumbra is apparent on the left edge.

Getting into the partial phase.

Almost into totality. The clouds are quite dense. This is a 4-second exposure.

The last trace of the Moon. A couple of minutes before totality. This is a 6-second exposure. The brown tint on the clouds is the wasted light from sodium vapour street lights which pollute the sky in the lower mainland.

Can you find the Moon in this picture?

Being into astronomy, the weather rules. It can be frustrating. I never got to see, or photograph any part of the remainder of this eclipse. There are many good pictures of all of the eclipse on the internet, taken in parts of the country which did not have cloud problems.

This was a really badly timed wipe-out.

Parks Astronomy

This last Saturday, the Vancouver Parks Board set up a public evening called "Night Quest" at the Pacific Spirit Regional Park. It involved naturalists talking about creatures of the night, and also included sky watching. To that end, the Vancouver Centre of the Royal Astronomical Society of Canada (RASC) was invited to participate. We had about 10 of our members (including me) set up telescopes in a parking lot which unfortunately is surrounded by trees and affords access to only a limited area of the sky. None-the-less, we could look at the planets Venus and Jupiter through the trees (no leaves yet), and occasionally also see the Moon. There were hundreds of people who got a glimpse of these through one or the other of the telescopes. My own scope was trained on Venus all evening. At the moment, Venus is in a position of its orbit around the Sun (as seen from Earth) which makes it look through a telescope like the first quarter moon. Many people mistook it for the Moon at first glance, and were amazed to see that Venus could look like that. Lively discussions followed regarding why such a thing happens. I think some people gained a much better appreciation of the geometry of our solar system.

Later, clouds covered up the sky, and we put our telescopes away. Just as the event ended at its scheduled time, the sky started to clear up again. We get suckered in like that quite often in this city.

I enjoyed the evening, explaining things astronomical to the public. I find that this is what I like most about doing astronomy now: public events, or astronomy nights with other members at our standard venues. These events are all open to the public. The scientific contributions I used to make when I was in my teens and twenties (mostly regarding variable stars) are no longer my main interest in that field.

Some additional information about things astronomical, not necessarily involving Vancouver Parks:

There are several interesting astronomical events coming up this year. Two interesting ones are an "annular" eclipse of the Sun late in the afternoon on May 20 and a transit of Venus across the Sun (again, as seen from Earth). The best place to see the annular eclipse would be for us to go to Redding, California, or Reno, Nevada, but we'll see a partial solar eclipse from Vancouver, too. The other event, the transit of Venus directly across the Sun on June 6, will again happen late in the afternoon. It will be visible from Vancouver, starting about 5 pm, and lasting into sunset.  Spanish Banks or any place with an open view of the Salish Sea (Georgia Straight) is a good spot from which to observe. This is the second of a pair of transits 8 years apart. The last one (the first of this pair) occurred on June 8, 2004.  The first one of the next pair happens on December 11, 2117, the second one of that pair on Dec 8, 2125.  I  don't think that I'll wait for those.

Annular solar eclipse, picture taken by RASC member Roy Bishop in 1994 near Sambro, Nova Scotia.














This image of the transit of Venus was taken by Murray Paulson, of St. Albert, Alberta,  at Hersonissos, Greece, on June 8, 2004















Both images taken from the Observer's Handbook 2012 published by The Royal Astronomical Society of Canada, editor David Chapman, printed in Canada by Webcom, Inc.

The December 10, 2011 lunar eclipse

Any hobby usually requires some "sacrifice". In my case, astronomy normally requires that I be awake and up while it's dark outside (the exception is when I'm using my telescopes to look [safely] at the Sun). A lunar eclipse always takes place when the Moon is full; the Moon is always exactly opposite the Sun then. At this time of year, the Sun rises low in the SE. That means that the Moon sets high in the NW.

This month's lunar eclipse occurred a couple of hours before sunrise, and I could watch it through my west-facing office window. I set up one of my cameras (a Canon Rebel XT SLR) and took some pictures through the double-paned window, and through breaks in the clouds. Before the eclipse started, the sky had been absolutely clear, but, just around the start of the eclipse, heavy clouds began to roll in. This is Vancouver, after all. Midway through the eclipse they totally obliterated any view of the eclipsed Moon. I got only one good picture through the last cloud break. These clouds kept the day dark and gray right through the next night, until the next morning.

Here are some of the pictures:

From the top down:

The Moon before entering Earth's shadow. The area at "11 o'clock" is getting darker.

Clouds are rolling in.

Three quarters into the Earth's shadow. Picture taken through a break in the clouds.

About 5 minutes before "totality" (again a break in the clouds). The star under the Moon is Iota Tauri (Iota in the constellation of Taurus, the bull)

The last "hole" in the clouds. The clouds to the right of the dark tree covered the Moon a short time later.

Midway through totality. This picture was taken just after the one above. About half-way through totality - the Moon has moved, so now is totally covered by the Earth's shadow. The brighter part of the Moon is closer to the edge of the shadow. Notice that the star Iota Tauri is now farther away from the Moon - it's a consequence of the Moon's motion in its orbit.

This is my last picture of this eclipse. A minute later, the Moon was completely covered by clouds and no longer visible.

The orange colour of the Moon in the Earth's shadow is due the sunlight being "refracted" by the Earth's atmosphere onto the Moon's surface. If you were on the Moon, you'd see the dark disk of the Earth surrounded by a reddish-orange ring (a circular sunset). From the Moon, this event is a total eclipse of the Sun. You'd have an awe-inspiring sight.

 The top picture was taken about two hours before the bottom one. It was a cold morning outside. This kind of thing did not bother me in the past, but now, in my old age, I enjoy creature comforts much more. I was glad to witness this in my nice, warm office.

Eclipse luck

Last night, as mentioned in one of my previous posts, the last total lunar eclipse for the next three years took place. The weather had been predicted to be cloudy, but about an hour before totality, the clouds started breaking up. Derek and I set up our cameras on our back porch, from where we had a clear angle of view. As the eclipse progressed, the cloud holes got bigger and bigger, so that by the time of totality we got a clear view for almost the whole length of the total phase. Clouds started to roll in about six minutes before the end of totality, and we missed the partial phases which followed.

Derek's wide angle shot of the eclipse.


About four minutes before totality. The sharp edge of the earth's shadow appears at the lower right of the moon. Exposure was 3/10 of a second at f11.

Derek and I got about 100 pictures between us. I was using my tried and true Celestron C90 telescope, coupled to my Canon Rebel XT (350D), Derek his Nikon D50, with a 210 mm zoom lens. Derek's images are here.
The picture (left) shows the moon around the middle of the total eclipse. The lower edge is brighter because it is nearer the edge of the earths shadow, through which the moon was moving at the time. Exposure time was 1 second, ISO 800, the scope is a fixed f11, 1,000mm focal length. Because the Rebel XT has a CCD area smaller than that of a 24x36mm film, the effect is about like that of a 1,500mm telephoto lens.


Here's my series:

Usually, when the weather forecasters are wrong, the error leans towards bad weather. This time, they were wrong and it turned into better weather - I can live with THAT. To see the eclipse, after expecting not to, felt like serendipity.