Orwell Astronomical Society (Ipswich)

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Lunar Total Eclipse, 17 October 1986

I looked forward to the lunar total eclipse on 17 October 1986 as I hadn't seen one for over ten years. Event times (UT) for the event were as follows:

I was pleased to see a clear blue sky when I got up, and the Breakfast Time weather forecast too was encouraging, although some cloud was due to arrive from the continent during the night.

After work, Roy Lobett and I went straight to the Observatory where we were joined by Gary Marriott. Roy and Gary brought with them cameras, loaded with black and white and colour films, fitted with 400 mm and 500 mm lenses. I fitted my SLR camera onto the 100 mm refractor fitted to the side of the main Orwell Park instrument. (The prime focus image of the smaller refractor covers approximately half of a 35 mm negative, whereas that from the larger refractor does not fit into a negative.)

The Moon was clearly visible at 18:10 UT in a blue sky although there were some worrying whisps of cloud near the horizon. By 18:15, it was apparent that the bottom left of the disk appeared darker than the rest and was, indeed, in deep penumbral shadow. By 18:30, when the umbral shadow began to cover the disk, all the cloud had melted away. At 18:48, I missed the opportunity for what would have been a classic photo: looking through the Orwell Park refractor I saw a high-flying passenger aircraft move directly across the middle of the lunar disk, showing up together with its vapour trail in silhouette against the partially-eclipsed Moon. The vapour trail was still visible when I took my next photo.

Around 19:00, the eclipsed portion of the Moon was obviously reddish in colour through the telescope although, to the naked eye, the bright, un-eclipsed portion of the Moon drowned out the subtle colouration. Also at this time, there occurred an invasion of children from Orwell Park School, who remained until totality, and were very impressed with the sight. This was in marked contrast to their response on seeing Halley's Comet in late 1985!

Just after 19:40, the Moon appeared totally eclipsed, and a coppery-red colour. Shorty afterwards, it disappeared completely, much to the surprise of everyone, until we realised that cloud was beginning to roll in. The eclipsed Moon reappeared briefly before being totally obscured by the thickening cloud. We departed when it became obvious that we were not going to see any more of the eclipse. Although initially disappointed at the premature end of our observations, we consoled ourselves with the thought that we had been lucky to see as much as we did.

More Information on Eclipses

See Fred Espenak's eclipse web site eclipse.gsfc.nasa.gov/eclipse.html.

Mike Harlow