Tonight – August 7, 2017 – just two weeks before the much-anticipated total eclipse of the sun on August 21, the full moon will pass through the northern part of the Earth’s dark umbral shadow, creating a shallow eclipse of the moon visible in Earth’s Eastern Hemisphere.
As with any lunar eclipse, the moon will sweep through the Earth’s shadow from west to east, even as the moon travels across our sky from east to west.
Photo at top: April 25, 2013 partial lunar eclipse from Sandy S. Palacpec Jr. in Los Baños, Laguna.
Any lunar eclipse can only happen at full moon, when the moon is opposite, or nearly opposite, the sun in Earth’s sky. That’s the only time that it’s possible for the moon to sail through the Earth’s shadow. Of course, to watch this lunar eclipse, you have to be on the night side of our world while the eclipse is taking place.
Looking at the worldwide map below, we can see that most of the world’s Eastern Hemisphere will be in a position to watch the eclipse.
This eclipse will be visible during the evening hours after sunset August 7 from the most of Africa and Europe. However, far-western Africa and far-western Europe (United Kingdom, Portugal, Scandinavia) will not see the partial umbral eclipse because the moon won’t rise until after the eclipse ends. As viewed from much of Europe and western Africa, the moon will actually be in eclipse as it rises in the east at sunset August 7.
By way of an example, we give the local eclipse times for Budapest, Hungary (August 7):
Partial umbral eclipse begins: 7:23 p.m. local time
Moonrise: 8:01 p.m. local time
Greatest eclipse: 8:20 p.m. local time
Partial umbral eclipse ends: 9:18 p.m. local time
In eastern Asia, Indonesia, Australia and New Zealand, the partial eclipse will occur in the morning hours before sunrise August 8. As for mid-Asia (India, western China), the eclipse will happen at late night or around midnight August 7-8.
Here are the local times of the eclipse for Tokyo, Japan, and Jaipur, India:
Toyko, Japan (August 8)
Partial umbral eclipse begins: 2:23 a.m. local time
Greatest Eclipse: 3:20 a.m. local time
Partial umbral eclipse ends: 4:18 a.m. local time
Jaipur, India (August 7-8)
Partial umbral eclipse begins: 10:53 p.m. local time (August 7)
Greatest eclipse: 11:50 p.m. local time (August 7)
Partial umbral eclipse ends: 12:48 a.m. local time (August 8)
As you can see from the above eclipse times, the partial umbral eclipse lasts for nearly two hours. We give these eclipse times in Universal Time (UTC):
Partial umbral eclipse begins: 17:23 UTC
Greatest eclipse: 18:20 UTC
Partial umbral eclipse ends: 19:18 UTC
You must convert UTC to your local time. Here’s how to do it.
If you’d prefer, you can use these eclipse computers to find out the eclipse times in local time:
Although most of the Earth’s Western Hemisphere (which includes North and South America) will not see this partial umbral lunar eclipse, the solar eclipse coming up one fortnight (two weeks) later will be visible from a very wide swath of the Western Hemisphere.
The United States in particular will enjoy a ringside seat, as the rather narrow path of totality (roughly 60 miles or 100 km wide) will swing all the way across the continental U.S., from the U.S. West Coast to the U.S. East Coast, during daylight hours on August 21, 2017.
Bottom line: You have to be on the nighttime side of the world – in this case, in Earth’s Eastern Hemisphere – to witness the partial umbral eclipse of the August 2017 full moon. The southern portion of the full moon will dip into the Earth’s dark umbral shadow for nearly two hours, from 17:23 to 19:18 UTC on August 7, 2017. The Americas will not be in a position to see this event.
Bruce McClure has served as lead writer for EarthSky's popular Tonight pages since 2004. He's a sundial aficionado, whose love for the heavens has taken him to Lake Titicaca in Bolivia and sailing in the North Atlantic, where he earned his celestial navigation certificate through the School of Ocean Sailing and Navigation. He also writes and hosts public astronomy programs and planetarium programs in and around his home in upstate New York.