If you’re desperate to see a total lunar eclipse, don’t miss the one on November 8. Otherwise you’ll have to wait a long time — as in: So long there will have been two Avatar movie releases and a presidential inauguration by the time there’s another one in March of 2025. Trouble is: Not everyone is going to be able to see this one in all its glory. Plus, you may need a refresher on what a total lunar eclipse — sometimes referred to as a "blood moon" — actually is.
Here’s the deal:
The very start of the eclipse, at 8:02 UTC, will occur the morning of Tuesday, Nov. 8, meaning 3:02 a.m ET, and 12:02 a.m. PT. In practical terms for most people who will be able to observe the eclipse, this will mean staying up late the night of Monday, Nov. 7, or waking up super early on Tuesday morning. The full eclipse will begin at 5:16 a.m. ET, and end right around east coast sunrise at 6:41 a.m. ET. If you’re not a night shift worker or a new parent, set your alarm accordingly.
Roughly the area around the Pacific Rim — Eastern Asia, Australia, and the Western part of the Americas — will have a great view. All of Africa, most of Europe, and the Middle East, will not get to see this eclipse.
On the other hand, no one — no matter how favorable their vantage point — is guaranteed good eclipse viewing weather. If the local sky isn’t giving you a nice view of the eclipse for whatever reason, various websites, like timeanddate.com, offer livestreams.
A lunar eclipse is tougher to explain than a much simpler solar eclipse. When a solar eclipse occurs, observers on the ground — with their safety goggles equipped — can’t see the sun because it’s being, well, eclipsed by the moon wherever the moon is casting a shadow on Earth. From the standpoint of someone on Earth in the moon’s shadow, one disc in the sky slides in front of the other, and boom: Eclipse! Not so with a more confusing lunar eclipse, which would, frankly, be a lot easier to understand if you were watching it from the surface of the moon.
A lunar eclipse doesn’t completely obscure the moon from our view, because what’s eclipsing it is us. If not explained well, it’s hard to understand why a lunar eclipse is something more special than a new moon. A new moon is just a moon phase — a moon viewing angle, essentially — in which the shaded half of the moon is all we can see. That happens every 27 days. No biggie.
A lunar eclipse on the other hand can only occur during one moon phase: full, because we Earthlings can only cast our shadow on the moon when we’re positioned between it and the sun, and that only happens when it’s full. The rarity of a lunar eclipse is due to the moon’s orbit around us having its own off-kilter angle (which is why it almost always accompanies a solar eclipse in the weeks before or after). During a lunar eclipse, something crazy happens during that particular lunar cycle’s full moon: It enters Earth’s penumbra — our planet’s outer shadow — and then its umbra — its more direct shadow — where the sun’s rays no longer hit it directly. This causes multiple strange effects:
First, the moon will dim a bit when it’s within the penumbra.
Next, the moon will appear to have a bite taken out of it, as part of its face is significantly darkened by the umbra. This doesn’t mean it stops being a full moon, mind you.
Then, if it’s a total lunar eclipse, the moon will be enveloped by the umbra.
Once it’s in the umbra, when there’s no longer a contrast between the illuminated part, and the part in shadow, the moon becomes easier to see, but red.
If it’s a partial eclipse, the redness of the dimmer part of the moon will be visible, but less prominent because the part of the moon still in the penumbra will be so much brighter.
So to recap, if you were a prehistoric hunter-gatherer, over several hours you would see the full moon get consumed by a shadow, and dim almost completely. Then it would seem more visible, but tinged red red. Then it would get consumed by a shadow again, and then go back to normal. Your mind would be utterly blown.
During the eclipse, while the moon is in our planet’s umbra, it will appear to be a haunting red color. Sunlight includes every color in the visual spectrum (and more!), but when Earth is blocking the sun, the light hitting the moon is passing through Earth’s atmosphere. From our vantage point on Earth, the various wavelengths of sunlight are all scattered differently depending on the sun’s angle, and the shorter smaller wavelengths of blue light are easier to see when the sun is shining on something directly. When it’s partially obscured, or at an angle — like at sunrise or sunset — reds and yellows overwhelm the blue. The same thing happens when the Earth’s shadow passes over the moon, and thus: The "blood moon" effect.
Again, this would seem quite simple if you were standing on the moon when it happened. The daytime sun would simply pass behind the dark Earth. Earth would suddenly have a bright, reddish, glowing corona around it, and your lunar surroundings would be bathed in dim orangish light. It would be like being bombarded by every Earth sunrise and sunset all at once.
