Recorded on August 28th [
http://www.spacewea…gallery_28aug07_page 2.htm ], this serene total lunar eclipse sequence looks southwest down Kalamalka Lake toward the lights of Coldstream [
http://maps.google.…BC, Canada&ie=UTF8 &ll=50.225355,-119.2 68951&spn=0.240294,0 .320663&t=h&z=11&om= 1 ], 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 [
http://www.mreclips…]. Around 270 BC, the Greek astronomer Aristarchus [
http://www-groups.d…Mathematicians/Arist archus.html ] also measured the duration of lunar eclipses - though probably without the benefit of digital clocks [
http://itotd.com/ar…revenge-of-the-analo g-clock/ ] and cameras. Still, using geometry, he devised [
http://www.phy6.org…] a simple and impressively accurate way to calculate the Moon's distance, in terms of the radius of planet Earth, from the eclipse duration.
Explanation
Recorded on August 28th [
http://www.spacewea…gallery_28aug07_page 2.htm ], this serene total lunar eclipse sequence looks southwest down Kalamalka Lake toward the lights of Coldstream [
http://maps.google.…BC, Canada&ie=UTF8 &ll=50.225355,-119.2 68951&spn=0.240294,0 .320663&t=h&z=11&om= 1 ], 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 [
http://www.mreclips…]. Around 270 BC, the Greek astronomer Aristarchus [
http://www-groups.d…Mathematicians/Arist archus.html ] also measured the duration of lunar eclipses - though probably without the benefit of digital clocks [
http://itotd.com/ar…revenge-of-the-analo g-clock/ ] and cameras. Still, using geometry, he devised [
http://www.phy6.org…] a simple and impressively accurate way to calculate the Moon's distance, in terms of the radius of planet Earth, from the eclipse duration.
Explanation
