Monday, September 28, 2015

Total lunar eclipse, September 27, 2015

September 27, 2015 was the night of the last of a series of four consecutive total lunar eclipses - and the last total lunar eclipse for several years.  While I was able to get some images of the last total lunar eclipse visible from Nanticoke, at that time I was still figuring out some of the most useful features of my camera. I was also operating under a time constraint (had to wake up very early, would have to pack things up early to get to work) and in a limited space (the Nanticoke-West Nanticoke bridge) in chilly conditions as the sun was rising.

None of that applied here. Sunday was the last day of my work week, so I technically was free the next day. (Except for Jury Duty, for which I would have to be out of the house earlier than usual.) The eclipse would take place in the evening over Nanticoke, late enough to be dark but not too late. And it would be visible from my back yard - in theory, anyway. The WNEP meteorologists were giving us a 40% chance of clear skies. I decided I would be happy with broken cloud cover.

I got to see everything.

All pictures taken with a Nikon Coolpix p520 mounted on a tripod. Camera set to automatic mode with focus at infinity. Magnification is maximum 42x for all but the last image. All photos were done using a 2 or 10 second self-timer delay to minimize shutter bounce. All pictures are raw and unprocessed except for size.

9:03 PM. While the umbral phase of the eclipse was supposed to start at 9:07 PM , there seems to be a good deal of umbral shadow already on the left side of the Moon. 
So, funny story: I base all my timings on what the clock on my camera says. I mean, if a $7.88 watch from Walmart set to atomic clock time can be trusted to keep one-second accuracy for weeks or months, then surely the built-in clock on a relatively expensive Turns out my camera clock was running four minutes fast. Which would explain why some of the images I got weren't exactly what I expected: I was four minutes too early.

9:06 PM. Umbral darkening obvious. Remember, this shadow is being cast obliquely along the edge of the Moon. 
The picture above should have been just before the umbra (the dark center portion of the shadow of the Earth) began to cover the left side of the Moon. Instead, it seems like the umbra reached out a bit further than expected. Extra-cloudy conditions in the upper atmosphere, perhaps?

9:20 PM. The curvature of the Earth's umbra is obvious now.
9:39 PM. Umbral shadow nearly halfway across the Moon.
9:54 PM. Umbral shadow most of the way across the Moon.
10:17. A few minutes before totality. Note the stars around the Moon. 
So I was wondering why, at totality (10:20 PM), a very bright edge of the Moon still seemed obvious. Turns out it was because totality was still three minutes in the future!

10:36 PM. Nine minutes into totality.
OK, now that's a totally eclipsed Moon!

10:50 PM. Three minutes past "maximum eclipse," the midpoint of totality, but exactly the published time of the Full Moon!
The midpoint of totality was scheduled for 10:47 PM, while the moment of "Full Moon" was calculated as 10:50 PM.

10:51 PM. Zoomed out to show the stars around the Moon. At totality the Moon hangs in the sky like a fading ember against a starry background.


As 11:00 PM rolled around I decided to call it a night. My alarm would be going off in a few hours and I would be off to my first day of Jury Duty. I posted some raw images to Facebook directly from my memory chip, looked at what other folks were posting, cleaned up the mess I had made with food and drinks while I kept yo-yo-ing between taking photos and posting photos. I shut everything down, put away my tripod and camera, and closed up my Chromebook.

I stepped outside to get one last look. Eyes-only, no camera.

A bright line was showing along the lower left of the Moon. The umbra was sliding away. No, that's not right. The Moon was continuing its journey in orbit around the Earth, and was sliding past the umbra.

Whatever frame of reference you use, the last total lunar eclipse of this series was over. Time for bed.

1 comment:

David DeCosmo said...

Very nice series of photos wit a camera far better than the one I was using. Good job. I really enjoyed seeing these photos! Thank you!