The first of four consecutive total lunar eclipses -- that riveting "blood moon" -- has occurred. The tetrad has begun!
Depending on whether you ask a mystic or a scientist, it may or may not be a sign of the apocalypse. But it could be comforting to note that there are eight sets of tetrads in the 21st century.
There have been periods without tetrads of total lunar eclipses, but NASA's eclipse guru Fred Espenak calls the phenomenon a relatively "frequent occurrence," at least in the current pattern of eclipses.
But which of the upcoming eclipses will provide the best show?
[Updated 7:43 a.m. April 17: "Of the three remaining, the longest two are Oct. 8, 2014, and Sept. 28, 2015," Alex Young, solar physicist at NASA Goddard, told the Los Angeles Times. "Also, those two eclipses are the only ones for which at least some of the continental U.S. will see a total eclipse."]
Making the Oct. 8 eclipse extra special: The moon will appear 5.3% larger than it did during Monday night's event, according to NASA.
As with the recent eclipse, the West Coast should get a good view of the fall event. California should be able to see it from start to finish, weather permitting. NASA says the northwestern third of North America will be able to see all stages of the eclipse.
The viewing from Southern California begins to diminish with the third eclipse in the tetrad, on April 4, 2015.
The time spent in totality -- the period when the moon is completely in Earth's shadow -- also plummets to just a few minutes.
For comparison, here's the totality of each of the eclipses in this tetrad:
April 14-15: 1 hour, 17 minutes, 48 seconds
Oct. 8: 58 minutes, 50 seconds
April 4, 2015: 4 minutes, 43 seconds
Sept. 28, 2015: 1 hour, 11 minutes, 55 seconds
The final eclipse of the four favors the folks back East. The East Coast and much of the Midwest will be able to view the entire eclipse. Those of us on the West Coast will be able to see the eclipse at moonrise.
So the best show for Southern California is coming up on Oct. 8. The worst bet is next April's event. As Young says: "The April 4 eclipse is only a measly four minutes and none of the total eclipse will be visible in the continental U.S."
Espenak waxed poetic in a recent news release on the total lunar eclipses. He urged readers to imagine themselves on the surface of that blood moon -- so called because of its reddish appearance -- during the height of a total eclipse.
"You might expect Earth seen in this way to be utterly dark, but it's not. The rim of the planet is on fire! As you scan your eye around Earth's circumference, you're seeing every sunrise and every sunset in the world, all of them, all at once."
Image credits: Eclipse map/figure/table/predictions courtesy of Fred Espenak, NASA/Goddard Space Flight Center