2015 Harvest Moon Total Eclipse

Date: Sep 27-28, 2015
Time: totality from 2:11 UT to 3:23 UT
Place: depends where you are on the Earth

Observers in most of North and South America will be well-situated to observe this total lunar eclipse. It starts around sunset and continues into the early morning hours. Provided below are the UTs for each phase of the eclipse. To convert times from UT to your local time, check out our Local & UT page and note the correction factor.

Partial umbral eclipse begins: 1:07 UT
Total eclipse begins: 2:11 UT
Greatest eclipse: 2:47 UT
Total eclipse ends: 3:23 UT
Partial umbral eclipse ends: 4:27 UT

Observers in other parts of the world can refer to the eclipse visibility chart at EarthSky.org. That page also includes a nice animation showing what the eclipsed Moon will look like. If you find yourself on the wrong side of the globe, or on the right side but clouded out, there will be live streaming from many locations. Here's one: http://www.eclipse-live.com/

You might hear this event referred to as a "Blood Moon." That's because the Full Moon's color goes from its usual bright gray before the eclipse, to a hue that can range from deep orange to deep red. Sometimes a non-eclipsed Moon can look a little orange near moonrise and moonset, but that's an atmospheric effect. For a comparison of that effect with a lunar eclipse, see this post.

For those unfamiliar with the physics of lunar eclipses, just play the animation above. Basically, a lunar eclipse happens when the Moon passes into Earth's shadow. It might seem from the animation that this should occur every month as the Moon moves along its 27.3 day orbit around Earth. But this animation shows a view from above the North Pole, and omits a critical feature of the real motion: The Moon's orbit is tilted with respect to Earth's orbit by a little over 5°, so more often than not, it passes either above or below Earth's shadow. There's a nice side-view animation of that motion here.

This eclipse is remarkable for several reasons:

  • It's the fourth and final eclipse of the current tetrad series.
  • It's also the largest Super Moon of 2015 — about 14% larger than its minimum, and up to 30% brighter.
  • It's also this year's Harvest Moon, so it will move on a longer arc through the sky (northern hemisphere).

I bid you clear skies for this event. The next Super Moon lunar eclipse won't happen until 2033. So turn out your yard lights, get a comfortable reclining chair, and enjoy this celestial show. You might even consider hosting a Tsukimi.

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