The last lunar eclipse of the year, and the last total one until 2014, will turn the Moon red for some lucky viewers.
The eclipse will kick off as the Moon passes though the shadow of the planet at 14:06:16 UT on 10 December. Viewers in the Western US and Hawaii will get a glimpse just before moonset, but the best views will be in Asia, Australia and New Zealand, who will see the full 51 minute eclipse. The lower the eclipse in the sky, the larger and more red it will appear to viewers.
“This is a special eclipse as it occurs as the Moon ‘leaps’ between the horns of the zodiacal Bull. We are hoping to see the Moon turn spectacular rust red as this happens,” said Dr Andrew Jacob, acting curator, Sydney Observatory, in a statement.
Astrology has nothing to do with it of course. The reddish tinge is imparted to the Moon by the amount of particulates in the atmosphere and the lensing effect of the atmosphere, which will also make it appear larger than normal for watchers.
"I expect this eclipse to be bright orange, or even copper-colored, with a possible hint of turquoise at the edge," predicted Richard Keen of the University of Colorado.
"During a lunar eclipse, most of the light illuminating the moon passes through the stratosphere where it is reddened by scattering. If the stratosphere is loaded with dust from volcanic eruptions, the eclipse will be dark; a clear stratosphere, on the other hand, produces a brighter eclipse. At the moment, the stratosphere is mostly clear with little input from recent volcanoes."
While a stunning special in itself, the eclipse will also allow stargazers good views of other objects, by cutting out a major source of light pollution. In an advisory NASA suggests that astronomers might use the opportunity to get a really good look at Aldebaran, Betelgeuse, Pollux and Capella. ®