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| A composite of ten pictures shows the progress of a total lunar eclipse |
Lunar Eclipse to Last a Hundred-Plus Minutes
Because of the tilt of the moon's orbit around Earth, the moon usually passes slightly above or below Earth's cone-shaped shadow, so no lunar eclipse occurs.Sometimes, however, the geometry is just right for the moon to cross Earth's orbital plane—always during a full moon. As all three bodies line up, the moon passes through Earth's shadow and we see a lunar eclipse.
Partial eclipses happen when the moon grazes Earth's shadow, while total eclipses occur when the whole moon passes through the shadow.
On June 15 Earth's shadow started to darken the moon around 18:22 universal time, or UT (2:22 p.m. eastern time).
The total lunar eclipse will began at 19:22 UT and will last for more than a hundred minutes. The deepest part of the eclipse will occur at 20:12 UT, as the moon plunges into the umbra, the dark center of our planet's shadow.
The last hint of Earth's shadow will slip off the moon around 22:02 UT.
The whole spectacle will of course be available to the naked eye as well—provided you're in the right place at the right time.
Except for northern Scotland and Scandinavia, most of Europe as well as eastern South America and western Africa will see totality underway around moonrise—just as the sun begins to set on June 15.
"The best place to be is where you would be able to view the moon throughout the eclipse—and the higher in the sky it is, the better," Burress said. "From that standpoint, the best location for viewing the entire eclipse is eastern Africa, the Middle East, Central Asia, and the western tip of Australia."
From Indonesia to New Zealand, viewers will get to see the moon's face slowly eaten away by the initial stages of the lunar eclipse just before the moon sets on June 16.
This celestial event won't be visible from North America, unfortunately for Canadian, Mexican, and U.S. eclipse hunters, who will have to wait until December 10, when western parts of the continent will be treated to the next lunar eclipse.
The most spectacular and least predictable part of the eclipse is the color the lunar orb will take on during totality, Burress said.
"The redness of the moon during totality depends partly on global atmospheric conditions," Burress said. That's because the light we see coming from the moon is actually reflected sunlight.
During a total lunar eclipse, Earth blocks the pure white, direct light from the sun. But some indirect light passing through Earth's atmosphere still manages to reach the moon.
Since dust and gases in Earth's atmosphere filter blue wavelengths from sunlight, the remaining light is reddened. The moon will therefore appear to change from brilliant silver to between bright orange and blood red during a lunar eclipse.
"Also, how high in the sky the moon is during totality has an effect: The lower in the sky, the more atmosphere its light must pass through to reach the observer, and the more reddening that can occur."
The best advice for sky-watchers is to get away from city light pollution as much as possible and go to places where there are no trees or houses blocking your view, Burress said.
"If you can determine where the moon will be during the eclipse, you want to choose a place with a clear, unobstructed view of that part of the sky and enjoy the show."