by APOD Robot » Mon Sep 28, 2015 4:06 am
Total Lunar Eclipse over Waterton Lake
Explanation: Recorded in 2014 April, this
total lunar eclipse sequence looks south down icy Waterton Lake from the
Waterton Lakes National Park in Alberta, Canada, planet Earth. The most distant horizon includes peaks in
Glacier National Park, USA. An exposure every 10 minutes captured the Moon's position and eclipse phase, as it arced, left to right, above the rugged skyline and Waterton town lights. In fact, the sequence effectively measures the roughly 80 minute
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. This modern eclipse sequence also tracks the
successive positions of Mars, above and right of the Moon, bright star
Spica next to the reddened lunar disk, and Saturn to the left and below.
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[url=http://apod.nasa.gov/apod/ap150928.html][img]http://apod.nasa.gov/apod/calendar/S_150928.jpg[/img] [size=150]Total Lunar Eclipse over Waterton Lake[/size][/url]
[b] Explanation: [/b] Recorded in 2014 April, this [url=http://apod.nasa.gov/apod/ap140416.html]total lunar eclipse[/url] sequence looks south down icy Waterton Lake from the [url=http://www.pc.gc.ca/eng/pn-np/ab/waterton/index.aspx]Waterton Lakes National Park[/url] in Alberta, Canada, planet Earth. The most distant horizon includes peaks in [url=http://www.nps.gov/glac/index.htm]Glacier National Park[/url], USA. An exposure every 10 minutes captured the Moon's position and eclipse phase, as it arced, left to right, above the rugged skyline and Waterton town lights. In fact, the sequence effectively measures the roughly 80 minute [url=http://www.youtube.com/watch?v=vYPUfzzux3E]duration of the total phase[/url] of the [url=http://www.mreclipse.com/Special/LEprimer.html]eclipse[/url]. Around 270 BC, the Greek astronomer [url=http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Aristarchus.html]Aristarchus[/url] also measured the duration of lunar eclipses - though probably without the benefit of [url=http://itotd.com/articles/297/revenge-of-the-analog-clock/]digital clocks[/url] and cameras. Still, [url=http://www.phy6.org/stargaze/Shipprc2.htm]using geometry, he devised[/url] a simple and impressively accurate way to calculate the Moon's distance, in terms of the radius of [url=http://science.nasa.gov/earth-science/]planet Earth[/url], from the eclipse duration. This modern eclipse sequence also tracks the [url=http://apod.nasa.gov/apod/ap141028.html]successive positions of Mars[/url], above and right of the Moon, bright star [url=https://en.wikipedia.org/wiki/Spica]Spica[/url] next to the reddened lunar disk, and Saturn to the left and below.
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