Lunar eclipse on winter solstice first in 372 years
Published Monday, December 20, 2010 9:33PM EST
Many Canadians will be staying up late tonight to catch a glimpse -- weather permitting -- of a rare and spectacular phenomenon as the moon enters the Earth's shadow.
The event itself isn't that rare -- lunar eclipses take place about twice a year. However, this eclipse is the first in 372 years to occur on the winter solstice -- the first day of winter marked by the shortest day and longest night of the year.
During a solar eclipse, the moon passes between the Earth and the sun. But during a lunar eclipse it's the Earth that is sandwiched between the sun and the moon.
"You see what looks like the shadow of the Earth crossing the moon, but it's really the moon entering the Earth's shadow and passing through, because it is orbiting the Earth," Calgary astronomer Alan Dyer told CTV News Channel Monday afternoon. "So you're seeing the orbital motion of the moon."
Eclipse timeline (all times in Eastern Time):
- 1:33 a.m. -- Partial eclipse begins
- 2:41 a.m. -- Total eclipse begins
- 3:53 -- Total eclipse ends
- 5:01 -- Partial eclipse ends
While various cultures and religious groups have attached significance to the occurrence of a lunar eclipse, it has also helped astronomers to learn more about Earth and its place in the solar system, astronomy expert Andrew Fazekas told CTV's Canada AM.
"When you look at that shadow creeping across the surface of the moon you will see that it's kind of curved, and guess what? It's curved because our planet is round and there you have it, the proof that our planet Earth is round, right in front of you," he said.
"Ancient Greek astronomers noticed this over 3,000 years ago and said this was proof that our planet was round."
Unlike a solar eclipse, a lunar eclipse is perfectly safe for viewing with the naked eye. However, it is best seen through binoculars or a telescope, which allows the viewer to see the motion of the Earth's shadow as it crosses the moon.
Something else that sets a lunar eclipse apart is the colour. The moon usually appears to be a shade of red, ranging from bright orange to deep red, during the eclipse.
"That's the beautiful part to watch," Dyer said. "The moon turns a deep red colour, it looks like a glowing red lantern in the sky. It's going to be a beautiful effect."
The last lunar eclipse that was visible throughout North America took place in February 2008, and the next one will occur in April 2014. According to Dyer, the next time a lunar eclipse occurs on the winter solstice will be 2094.