Home » Education » Science » Astronomy and Space

Learn About Lunar Eclipses

7 Like

Like 7

Pin It

Ranked #21,515 in Education, #442,934 overall

About 500 years ago, a lunar eclipse saved Christopher Columbus from the wrath of angry islanders.

Marooned on the sandy shores of Jamaica in 1503, the explorer and his crew depended on the hospitable natives for food and supplies. But, as we know from history books, Columbus wasn't always the gracious guest. Arrogant and rude, the explorer alienated the very people he relied on for survival.

As a result, the natives got restless and cut off all aid to the sailors. Columbus, of course, would not tolerate such actions. After consulting his almanac and sand glass, the navigator, who used the stars to guide him through oceans, knew that there'd soon be a lunar eclipse, which would cause the moon to vanish as it passed through the Earth's shadow

"Columbus told the natives that if they did not cooperate he would confer with God and remove the moon from the sky," says Fred Espenak, a leading expert on eclipses and an astrophysicist at NASA's Goddard Space Flight Center in Maryland.

The natives thought Columbus was bluffing, but then they watched one of the brightest objects in the sky fade into the night. "They were terrified," tells Espenak. As with all lunar eclipses, the moon eventually reappeared. "When it came back, the locals repented and the supplies started flowing." About four months later, Columbus and his crew were rescued

Earth casts a fair shadow

The Moon and How to Observe It (Astronomers' Observing Guides)

by: Peter Grego

Amazon Price: $25.38 (as of 06/02/2012)

During a total lunar eclipse, the moon doesn't simply fade to black. In fact, it often takes on a reddish hue, ranging from peach to crimson. This has to do with the way the atmosphere scatters sunlight.

"The light that reaches the moon during a lunar eclipse is filtered and bent," explains Espenak. "Most of the blue light has been removed by the Earth's atmosphere." What remains is mostly red light, which reaches the moon and reflects back toward Earth. Without the Earth's atmosphere, the moon during a lunar eclipse would look like a lump of coal suspended in the night sky.

Because the atmosphere plays a role in what color the moon appears during an eclipse, the particles in the atmosphere also play a role. For instance, the volcanic ash that Mount Pinatubo spewed into the upper atmosphere in 1991 changed the color of the six lunar eclipses that followed. Some were so dark that the moon was nearly invisible. Despite the fact that more than 12,000 eclipses - both partial and total - will have occurred from 2,000 B.C. to 3,000 A.D. (Espenak has calculated the timing of them all), very few ever look alike.

Besides atmospheric conditions, the moon's path through the Earth's shadow also makes each one unique. During the total lunar eclipse of July 16, 2000, the moon was in the umbra for 1 hour and 47 minutes - the maximum duration possible.