Sky watchers in Western Canada had an opportunity to observe a total lunar eclipse early Saturday morning — for the last time until 2014.
The Earth's shadow covered the moon completely for a little over 50 minutes, starting at 6:05 a.m. PT on Saturday.
According to NASA, the peak of the eclipse, when the moon appears red or orange, took place at 6:30 a.m. PT. That was roughly 1½ hours before the sun was scheduled to rise and the moon was scheduled to set in Vancouver.
Why does the moon turn red?
The moon turns orange, red or brown during the peak of a total lunar eclipse. Normally, it appears grey or white as it reflects sunlight that shines on it directly — a combination of all colours of the spectrum visible to our eyes. However, during a total lunar eclipse, the Earth's shadow blocks the direct sunlight. Any light that still reaches the moon must first pass through the Earth's atmosphere. The atmosphere filters out most of the blue light so that mainly the red light makes it to the moon.
The peak took place well before dawn across most of Canada. Unlike solar eclipses, lunar eclipses are perfectly safe view without any eye protection. The total eclipse was best viewed from Australia, China, Southeast Asia, Japan, and in Russia east of the Ural Mountains.
David Sayre of Hawaii remembered to wake up early, around 3 a.m. local time, to view it. Sayre said it had been cloudy and rainy around his house on Oahu, but the weather cleared just in time.
"Sure enough it was turning that orangey-red colour," Sayre said. "To be able to see it just right outside our house was really cool."
This is the second total lunar eclipse of the year — another one took place in June, but during the daytime in North America. It was visible in Europe, Asia and Africa.
The next total lunar eclipse visible from North America won't take place until April 15, 2014, NASA says. However, a partial lunar eclipse will be visible in Eastern Canada around dawn on June 4, 2012, Sky and Telescope magazine reports.
NASA took advantage of Saturday's eclipse to take measurements with its Lunar Reconnaissance Orbiter. The unmanned spacecraft, which has been orbiting the moon since June 2009, will measure how quickly areas of the moon's day side cool off during the eclipse. The rate of cooling will depend on the composition, density, and rockiness of the lunar surface.