How to Watch Saturday's 'Blood Moon' Total Lunar Eclipse

Be sure to set your alarm extra early on Saturday (or, conversely, stay up really late on Friday) so you can catch the first of this year's two total lunar eclipses.

All of North America (and most of South) will be privy to at least some of the eclipse before "moonset." However, only those on the West Coast will have a chance to see the total eclipse phase before it drops below the horizon.

According to timeanddate.com, East Coast sky watchers will see the moon fall into the Earth's shadow a little after 5 a.m. local time, and the eclipse will reach its relative peak at 6:30 a.m. just before it sets (so, all you East Coasters will need a clear view of the western horizon if you hope to see anything).

As we head west, the celestial show begins earlier in the morning (or evening, depending on where you are) and will start while the moon is higher in the sky. In Chicago (and associated longitudes), for example, the eclipse will begin at 4:01 a.m. local time, while in Phoenix, things kicks off just after 2 a.m. local time. Every part of the U.S. west of Salt Lake City will be able to catch at least some of the total phase of the eclipse before it's gobbled up by the horizon, and Hawaii and western Alaska will be able to take in the eclipse in its entirety (where things start anywhere between 11 p.m. and 1 a.m. local time respectively).

Of course, if the clouds decide not to cooperate, you won't see anything no matter where you are. However, if you still want to check out the action, or just want to join in with the community of upturned necks, the crowd-sourced astronomical society Slooh.com will offer a free live stream from their observatories along with expert commentary (feed is embedded below).

According to NASA (PDF), this eclipse—for those who are on the right side of the planet—will last a total of 5 hours, 57 minutes, and 32 seconds. If this is your first lunar eclipse, they unfold in a very predictable manner: First, the moon passes into the outer, semi-illuminated part of the Earth's shadow (the penumbra). During this initial phase, the moon appears to dim from white to dark gray over the course of an hour or so. Next, the moon begins to slip into the darkest part of the Earth's shadow, the umbra, at which point it will transition from dark gray towards a reddish-brownish hue.

An hour and a half after entering the Earth's umbra, the moon will fall completely enter the burgandyish embrace of the Earth's umbra, where it will remain for four minutes and 43 seconds before transitioning back to the usual moon we all know and occasionally fire rockets at.

Blood Moons Aren't Actually Things
You may have noticed that some media outlets—including some that should really know better—have begun utilizing the spooky-sounding, yet meaningless phrase "blood moon." This phrase suggests that the red hue that will result from the moon dipping into the Earth's umbra is somehow novel, when it actually happens during ev-er-y total eclipse.

This reddining is the result of the sunlight passing through the Earth's atmosphere and refracting red light onto the otherwise unilluminated lunar surface. There is absolutely nothing special going on with this or any other total lunar eclipse. Well, almost absolutely nothing special (and this is where some people—especially those of certain medieval inclinations—get confused).

Saturday's eclipse is the third of an uninterrupted four-part series of total lunar eclipses known as a lunar tetrad. Lunar eclipses are regular occurrences (there are roughly two a year), however only about a third are total eclipses (as opposed to partial eclipses, in which the moon doesn't pass completely into the Earth's umbra). So, it's a somewhat rare event when the Earth experiences four total eclipses in a row without any partial eclipses in between. To reiterate a point: a lunar tetrad is only somewhat rare. The last one was in 2003, and there will be six more before the current century is through. So, you can count on experiencing a lunar tetrad roughly once a decade.

The current tetrad (which included total eclipses on April 15 and Oct. 8 of last year, and will conclude with an eclipse on Sept. 28) has captured the attention of some biblical literalists who have embarked on some textual acrobatics to manufacture prophecies involving "blood moons" that are somehow involved with the current tetrad. It's all old-time-religion logic barf. But that hasn't stopped the media from taking on the meaningless phrase because it sounds cool.

So, there you go. The eclipse is very cool, but "blood moons" are very dumb. And if you miss this eclipse for some reason, don't worry, there will be another one in late September. So, keep lookin' up! There's cool stuff up there!