Kalamalka Lake Eclipse

Astronomy Picture of the Day · 2007-09-01 · NASA (public domain)

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Kalamalka Lake Eclipse — APOD for 2007-09-01

Recorded on August 28th , this serene total lunar eclipse sequence looks southwest down Kalamalka Lake toward the lights of Coldstream , British Columbia. An exposure every 4 minutes captured the Moon's position and eclipse phase, until the Moon set behind the town lights and a hill on the horizon. In fact, the sequence effectively measures the duration of the total phase of the eclipse . Around 270 BC, the Greek astronomer Aristarchus also measured the duration of lunar eclipses - though probably without the benefit of digital clocks and cameras. Still, using geometry, he devised a simple and impressively accurate way to calculate the Moon's distance, in terms of the radius of planet Earth, from the eclipse duration.

Astronomy Picture of the Day for 2007-09-01 — image & explanation courtesy of NASA (public domain), mirrored at Tukuk-OS for reading and search convenience.

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