According to a long and informative post at space.com, tomorrow will be a rare “annular” eclipse, where parts of the world (unfortunately not mine) will be able to see the Moon blotting out the Sun except for a ring of the Sun’s light around the edge. Sadly, most of our readers, who are in the U.S., Britain, Europe, and the Antipodes, won’t be able to see it, but if you’re in Spain or southern France you’re in luck. And the few readers in Africa and northern South America are in for a treat.
For most North American observers, the partial eclipse will coincide with sunrise. But within a very narrow corridor that extends for 8,345 miles (13,430 kilometers) across the planet, the disks of the sun and the moon will appear to exactly coincide, providing an example of the most unusual type of eclipse: a “hybrid” or “annular-total eclipse.”
During annular solar eclipse, the sun looks like a “ring of fire,” while the moon and sun line up perfectly during a total eclipse. Throughout a hybrid eclipse, however, the celestial sight transitions from annular to total.
Here is a video (path of eclipse is the pale, elliptical shadow that moves across the Atlantic) as well as a map of its path:
In the U.S., it starts at about sunrise: 6:45 ET (don’t forget to set your clocks back tonight!). If you’re sleeping then, you can watch it streamed live here.
Here’s what it will look like if you’re in the good zone:
Space.com has a lot of info, but I’ll just give a bit more:
During the 21st century approximately 4.9 percent of all central solar eclipses — those eclipses where the moon crosses directly in front of the disk of the sun — fall into the hybrid classification.
In most cases, an annular-total eclipse starts as an annular, or “ring of fire” eclipse, because the tip of the moon’s dark shadow cone — the umbra — falls just short of making contact with the Earth; so the moon appears slightly smaller than the sun producing the same effect as placing a penny atop a nickel leaving a ring of sunlight shining around the moon’s edge.
Then the solar eclipse transitions to total, because the roundness of the Earth reaches up and intercepts the shadow tip near the middle of the path, then finally it reverts back to annular toward the end of the path.
However, as pointed out by the renowned Belgian eclipse calculator, Jean Meeus, the hybrid eclipse of Nov. 3 will be a special case: here the eclipse starts out as annular, then after only 15-seconds it will transition to a total eclipse, and then it remains total up to the very end of the eclipse path. The last time this happened was on Nov. 20, 1854 and the next such case after 2013 will occur on Oct. 17, 2172.
Here’s a picture of a solar eclipse taken from space (the dark sphere in northern Africa is the moon’s shadow):