Monthly Archives: February 2020

Lunar Eclipse Sequence

Posted on by
Lunar Eclipse Sequence
Minnetonka MN, 20 Jan 2000, first image 8:55 pm CST
Nikon-F at prime focus of Takahashi CN-212 (Newtonian 820mm at f/3.9)
E200 Ektachrome

I have seen a total lunar eclipse before, but it was by accident, and I was unable to successfully photograph it. This time I knew it was coming and the skies were clear, but the brutally cold temperatures caused me to find excuses to stay indoors. I was goaded into it however by my son, who pointed out that I had acquired considerable cold weather gear, equipment, and specialized clothing for my peculiar hobby. If not now, when would I ever put them to use?

Of course to maintain any sense of pride, I quietly took his point and proceeded to set up in the neighborhood open area. It is directly under a streetlight which exposed my activities to the neighbors, whose curiosity was not deterred by the temperature. By the time the edge of the moon started to dim, a small group of kids and their hardy parents had assembled to see what would happen.

Our informal eclipse party would last for the next few hours, with people cycling through neighboring houses, returning with hot chocolate, warmed-up feet, and more participants. My own schedule called for taking an exposure every ten minutes, not quite enough time to leave my post.

It was enough time to explain what was happening and to show views though the telescope as the edge of the Earth’s shadow crossed the face of the moon. I like to explain that if we were on the moon, the Earth would be backlit, and that everywhere along its edge is at either sunset or at sunrise. The sky there is familiar to us: red and orange, the colors refracted slightly around the Earth’s edge by the air. It is this reddish-orange light source that illuminates the moon when the sun no longer hits it directly.

It is interesting that the edge of the shadow shows a bit of brownish cast. As the last bit of direct sunlight hits the very edge of the moon, the orange-brown shadow details emerge. It has been there all along, but our eyes can now adapt to this much dimmer light level.

These views are quite similar to the visual experience. At full totality however, the moon seemed to be a grayish brown color. The deep red in the photo is not artificial; the film sees it better than we do.

Andromeda Galaxy

Posted on by
Andromeda Galaxy 
Cherry Grove Observing Site, MN, 08 Oct 1999
E200 Ektachrome, pushed +2 stops
Superposition of two 20-minute exposures

The Andromeda Galaxy spans a portion of the sky that is larger than the full moon!  But a full moon would wash out the sky, making the galaxy hard to see, even with binoculars.  When the sky is dark it can be seen as a hazy smudge, making it the most distant object (more than two million light years away) that we can see with the naked eye.

In the eyepiece of a telescope the smudge becomes larger, but to detect the wonderful spiral structure and faint blue outer arms of this galaxy requires the light-accumulating power of a piece of film placed at the telescope’s focal point.  The stars in this picture are in the foreground, artifacts from our own galaxy, which we must look through to see into our neighbor’s part of the universe.

Climber Trails

Posted on by
Climber Trails
Mount Ranier National Park, 19 August 1999
Nikomat with 20mm lens at f/5.6
One-hour exposure on E200 push-processed +2 stops

The skies continued to hold clear, the temperature dropped, and the moon set by midnight, allowing me to compose a view of Polaris directly above the summit of this ancient volcano.

There are a number of interesting light sources in this picture.  The startrail arcs are made by a one-hour sweep of the Earth beneath the North Star.  The green glow of distant Seattle shows to the northwest, the amber of closer but much smaller towns are northeast,  and the sky itself illuminates the snowfields on the mountain.  An additional light source can also be found within the snowfields.

As I started this exposure, I could sense a faint glow that seemed to come from the slope of the mountain itself.  Training a telescope on the area, I found what might be unseen hikers bearing flashlights searching through the snow.  I was impressed that a flashlight could be seen at these distances.  Camp Muir, where climbers rest on their way to the summit, was four miles away!

I learned the next day that what I had seen was not just a couple of hikers resetting their tent stakes.  They had started their ascent to the summit!  In order to reach the top and get back down before the snow gets dangerously soft, they must strike out at about 1:00 A.M.  This photo captures their first hour of progress on a beautifully clear and starlit night (click to see full size image).

Rainier by Moonlight

Posted on by
Rainier by Moonlight
Mount Ranier National Park, 19 August 1999
Nikomat with 20mm lens at f/5.6
30 minute exposure on E200 push-processed +2 stops

I am told it is unusual to see the top of Mount Rainier.  The generally overcast skies of the region and the immensity of the mountain usually guarantee that clouds will somewhere get in the way of the view.  On this day however, the sky had been clear.  It stayed clear while the sun set, and as the glow of twilight was replaced by the feeble illumination of a young moon, I worked my way up the mountain’s shoulder to this site, aptly named Reflection Lake.

My daytime explorations had found this lake, but the surface had been broken everywhere by wind ripples.  Now the air stilled and the water became stable enough even for a time exposure of the mountain’s reflection.  I wanted to include some startrail features in this picture, but it is an awkward choice:  if the shutter is open too long, the moon would wash out the sky and the trails would be lost.  Too short, and the stars do not make sufficiently long marks.  This was my guess, 30 minutes, a balance between starlight and skylight.

This picture also answers the question, “what color is the sky at night?”  Maybe nocturnal creatures can see in color at night, but we don’t.  The moon lights up the world, including the sky, with reflected sunlight.  The same physics applies, just at lower levels of illumination, and so the sky is blue!

A few cirrus clouds stream past in the distance, but they’re not enough to keep the brightest stars from showing.  Four of them above and to the left of the mountain peak are the bowl of the Big Dipper, each bluish except for the brightest star in the constellation, Dubhe, a distinct orange color.

The moon set shortly after exposing this picture.  Its low angle is apparent from the long shadows on the distant snowfields.  My time in Rainier Park would end the next day, but this was a remarkable evening to finish my visit.