ATLANTA -- The moon will turn bright red Thursday night during a total lunar eclipse that should be easy to see throughout the Americas, an astronomer said Saturday.
The Earth's shadow will totally cover the moon from 9:05 p.m. MST on Thursday to 10:22 p.m."We're kind of expecting that this eclipse will be very bright and probably very bright red," astronomer Brad Schaefer, an expert on this phenomenon at Yale University, said at the American Astronomical Society meeting in Atlanta.
When the Earth's shadow passed over the moon, the brightest light visible from the lunar surface would be the reddish-orange light from the sun bending around the Earth, Schaefer said.
"This same thing happens to us (on Earth) during sunsets. When the sun has just set, you look off toward the direction of sunset and the same physics is going on, and so what you're seeing on the moon is basically sunset colors.
"In fact, what you're seeing is the sunset colors completely around the globe. You're seeing all of the world's sunsets and all of the world's sunrises simultaneously," Schaefer said. "If the brightest thing in the sky illuminating the moonscape is a bright red light, well, the moon will appear red."
The brightness of the color depends on whether there has been a recent volcanic eruption that has sent sulfurous compounds high into the stratosphere. Such an eruption, like the blast of Mount Pinatubo in the Philippines in '91, can turn the moon so dark that it is difficult to spot during an eclipse.
But since there has not been such an eruption, Schaefer and others have forecast a bright red lunar disk in the sky, appearing to be within the constellation of Cancer. No special observing equipment should be necessary, but a pair of binoculars might be helpful. Getting away from ambient light is also a good idea.
Human-made pollution does not affect the color of the moon during eclipse because it does not generally get high enough into the stratosphere, Schaefer said. Clouds might block the view, however.
Schaefer said eclipses in general and lunar eclipses in particular have universally been viewed as bad omens throughout history.
"In many societies the moon is depicted as being a god, a goddess typically, and if you have a lunar eclipse, it's like the death of a god," he said. "It's a rather scary thing."
Various historical figures have used these fears to their advantage, most notably explorer Christopher Columbus, whose accurate prediction of a lunar eclipse in Jamaica apparently persuaded natives there to continue to help Columbus and his crew, according to Schaefer.
More information on eclipses can be found at the Web site sunearth.gsfc.nasa.gov/eclipse/eclipse.html.