Total eclipse of the moon

Lunar Eclipse

Wednesday night a spectacular and beautiful total lunar eclipse took place, visible to most of the North American continent. It was, unsurprisingly, a very popular topic on blogs throughout the blogosphere yesterday, with lots of people posting photos of the event. Well, I might as well add my voice to the fray, and my photos, too, even though they’re pretty similar to just about everyone else’s.

I’m pretty sure this is the first lunar eclipse I can remember watching. I may have seen one or two before, perhaps when growing up, and have simply forgotten. In any case, I’d been thinking I should go out to watch it, but, ironically, it had slipped my mind that it was Wednesday night, caught up in a drawing I was working on. I was only reminded of it when my mom came and told me it was happening. So I missed out on the first part of the eclipse, and caught it midway through.

Lunar Eclipse

It was a pretty cool show. When I first stepped out it was glowing a reddish orange, with just the bottom “corner” outside the shadow. The last time I looked at it the eclipse was nearly done. It’s a shame it was so cold out, it really discouraged spending a lot of time watching if you didn’t have a good view through a window. It took me a while to get my camera setup right for long-exposure shots of a bright object. The tricky bit was figuring out how to get the mirror to lock up (the setting was buried in a second tier of the menu). I had the camera mounted on a tripod, and I’d recently bought a remote shutter release (the geek in me was excited about that purchase), but even just the slight shake as the mirror flipped up to take the photo was enough to create a blur in the image. Once I figured that out I was good to go.

I saw a lot of photos on the web, but very little explanation of what was going on as this show progressed, so I did a bit of poking around and found this informative site, which I’ll summarize. NASA also has a good page about the recent eclipse.

Lunar Eclipse

A lunar eclipse is caused by the moon (which has no light of its own, so simply reflects the light of the sun) passing through the earth’s shadow. The earth has two shadows, one from the sun’s direct rays, and then “thinner” shadows where the sun’s rays hit it at an angle (since the sun casts light from all points of its disc in all directions, the “lower” edge of the sun will cast light in the direction of the “upper” edge of the earth). The main shadow, from the direct rays, is called the “umbra”, and the “thinner” halo shadow surrounding it is called the “penumbra”. The penumbral eclipse is very difficult to discern with the naked eye, so all the photos and etc that you see online pretty much deal with the umbral eclipse.

The moon shows up reddish during an eclipse because the small portion of light that gets to it around the sides of the earth is bent and refracted and filtered through earth’s atmosphere, which results in only the red wavelengths hitting the moon. It’s this refraction that allows the moon to be visible during an eclipse; if earth had no atmosphere the moon would be black.

Lunar Eclipse

An eclipse can only occur during a full moon. It can also only occur when the moon passes directly behind the earth. Because of the way the moon orbits the earth, it’s usually offset enough that it passes above or below the earth’s umbral shadow when its orbit takes it behind the planet. This is why eclipses are so infrequent. Total eclipses, where the whole of the moon passes through the umbral shadow, are very rare, and partial eclipses, where just a portion is in shadow, are only slightly more common. Partial eclipses outnumber total eclipses 7 to 6 (not a big margin, is it?).

But infrequent is definitely a relative term. We don’t get a lunar eclipse every full moon, but it’s estimated that between 2000BC and 3000AD (a very long time-span, I’ll admit, at 5000 years and certainly outside of most people’s frame of reference), 7,718 eclipses (both partial and total) will take place. That’s about three every two years (1.5 a year). It’s possible to have up to three take place in a year. The last time that happened was in 1982.

The next total eclipse won’t happen until December of 2010. However, there will be a partial eclipse this August. Unfortunately, the Americas won’t be able to see it because it will take place while the moon is below our horizon. The next one the Americas will get to view will in fact be the 2010 total eclipse (western America will get to see a partial one earlier that year, as well). We’ll be treated to two total eclipses in both 2014 and 2015. Other parts of the world will see some that we won’t in the time in between.

Lunar Eclipse

Visible near the moon during this eclipse were two bright points of light. The one on the left, to the east, is Saturn, while the one to the upper right, to the west, is the bright star Regulus. I could see with my eye, but not capture with the camera, that the moon was sitting in the constellation Leo during the eclipse. The little blue crescent in the images I think is some sort of reflection or refraction from the glass of my lens. I kind of liked the effect it created, so left it in.

Stars in earth's rotation

While I was out there messing around with long exposures and night sky shots, I tried playing with a long exposure of the stars. The length of exposure on this shot was 240 seconds, or 4 minutes. It was taken with my long lens on the camera, at about 200mm (I think). The long streaks of the stars were actually created by the earth’s rotation, you can see a bit of a branch that’s stationary. I was surprised that they would be so pronounced with such a (relatively) short exposure!

Noon at night

Full moon... and city reflection

Last week a big storm system moved through southern Ontario, dumping a pile of snow in its wake. I love being out in the country for snowstorms, both during and after. It doesn’t get much prettier than giant fat snowflakes falling against a backdrop of evergreens and red dogwood. Once the storm has passed the whole world is blanketed in a smooth sheet of pristine white, untouched, as yet, by little feet. All the branches are lined with snow, creating definition among the forest trees.

That night was a full moon, and as I was going to bed I stopped to admire the long shadows of the big maples in the front yard, cast across the sparkling snow. As I often do, I tried to capture the scene with my camera. Although an interesting image, I’m not sure it really did justice to the magical feel of it.

The sky in the picture is pinkish-purple. When I took the picture, standing at the window with the lights off, looking out over the front yard, it was most definitely dark. The above image was shot with a 15 second exposure, enough to try to capture the crispness of the shadows and the brightness of the snow. In using such a long exposure, I also managed to capture some of the ambient light being given off by the town to the south.

City of Light

It’s called light pollution, and it’s as common and wide-reaching as people are. Although in rural areas, such as my parents’ home, it can be very subtle to discern (most of the time it’s manifested to our eyes as simply a rosy glow along the horizon), in the big city it can be incredibly bright. One lightbulb may not cast a lot of light on its own, but when you combine hundreds of thousands all together… Well, think of it as the difference between the candles on the cake brought in for your niece’s 6th birthday party versus those on your uncle’s 60th. You could probably illuminate the room with your uncle’s cake. The above photo of the city of Toronto, taken from a distance at night, really gives you an idea of the effect. The glow of the lights hangs over the city like a layer of smog.

Today we got another big dump of snow. If you believe what they said on the evening news, it could be record-breaking for amount of snowfall in a single day for the Toronto area (I’m sure places north and west of us would scoff at the paltry amount). It continues to snow even now, having begun before dawn today. It should be done by the time people are heading out to work tomorrow, but it will be a considerable accumulation.

City light reflection

Because it’s still snowing, it’s overcast. Clouds throw another wrench into the mix as far as light pollution goes. The above photo was taken using a similar 15 second exposure as the top photo, pointed out the side window instead of the front, but still generally toward the south. Instead of the pale pinkish-purple sky of the first image, however, we have a deep, vibrant orange. The trees are darker because there was no moon to illuminate them, but the sky is glowing. You can also see the streetlight at the home across the road (private, installed by the homeowners when they first moved to the country, for security I guess; it’s the only one on the street), and a thin ribbon of light as a car drove by during the long exposure (which I think is neat).

Clouds have excellent reflective properties, both of light and of heat, which is why overcast days are often warmer than clear, sunny days. They reflect a lot of the warmth trapped in the atmosphere back down to earth. Similarly, they also reflect a lot of the light cast on them from urban centres. If you’re out walking at night, particularly near town, you’ll find it easier to navigate on overcast nights than on clear ones because of this.

Light pollution in Toronto

This effect is amplified when you’re inside the light source. Our apartment sits over the garages of the building, and the floodlight illuminating the small parking lot also casts a lot of light on the surroundings. This is particularly noticeable after a good snow, such as in the above photo, taken last week. It can be so bright it almost seems like dawn. The exposure for the above photo was a paltry 1.6 seconds. I started washing the image out if I went any longer than that.

Light pollution in Toronto

This photo was taken looking south (from the west-facing windows) toward the lake from the apartment. There’s a very noticeable darkness on the horizon over the lake. I suspect (although I don’t know for certain) that this is the delineation between the clouds over the city, casting back all the light, and those over the lake, where there is no light to cast back.

Stars
(stars as seen looking lakeward from Tommy Thompson Park on the Toronto lakeshore; long exposure, of course)

When I was a kid I would go out stargazing with my dad, picking out the constellations from the dark starry sky. The big city and neighbouring local towns have all grown since then, and with the increased night light, the stars are fewer and harder to see. This change is noticeable to me, even within my relatively short lifetime, and I find it sad to think of what the sky will be like in another 20 years. When I travelled out to British Columbia a couple years ago, I lived in a small trailer in the bush in the Okanagan Valley. The sky resembled, to quote Incubus, “a backlit canopy with holes punched in it.” It was gorgeous, and something quite unlikely to be seen with any regularity in the Toronto area again.

In summer 2003 the eastern seaboard suffered a “Big Blackout”, and cities were completely darkened, treating their residents to a light show the likes of which probably many of them had never seen. On March 29 this year, at 8pm, Toronto will participate in Earth Hour, a one-hour event where (ideally) the city will turn its lights out on a scale approaching the Big Blackout. The idea behind this is to make a statement to governments and other powers that be on energy usage and climate change, and related environmental issues. Although it’s still a month and a half away, pencil it in on your calendar on March 29 to turn your lights off then head outside to enjoy the sky.