There are technically six phases, but First, Second, Third and Fourth Contact are the important ones to know. Second Contact is the money shot—and the final seconds before it are exhilarating.

First Contact

When the edge of the moon touches the sun.* Hooray! The eclipse has officially begun, and you’ll notice zero difference from the moment before. Keep your eclipse glasses or other protective eyewear on while looking at the sun. Go get a beer; you have about an hour to tinker with your telescope and chat up the other chasers before the real action begins.

Partial Phase One

The moon moves slowly to pass in front of the sun and the sky remains bright until the final ten or so minutes before totality. Clouds may form and disappear, causing widespread panic below. In the final few minutes before totality, daylight will eerily gray; watch for shadow bands on the ground and notice the drop in temperature, often up to twenty degrees. Confused night birds and insects may emerge. You may feel a vague, uncontrollable dread—you’re experiencing your home planet in a way you’ve never felt before. It’s not like twilight. Your beloved sun is growing faint, losing strength. (Reflect upon the way ancient man must have reacted.) Keep your eye filter in place until the last seconds, then whip it off just in time to see Baily’s Beads and everyone’s favorite phenomenon, the self-explanatory Diamond Ring.

Second Contact

This is it! TOTALITY. Our moon is now blocking our sun, and you’re standing in the umbra. Wispy white coronal streamers materialize and flow from the blackest, black hole in the sky. Red prominences (yes, you can actually see FLAMES ON THE SUN) are visible at the edge of the black disk. It’s okay, scream and clap; try not to be the “woo guy”. No shame if you cry—at least one person near you will be openly sobbing. Some say it’s like looking into the eye of God. Wrench your eyes away for a few moments to observe the colorful 360° twilight on the horizon and the constellations that are always up there during the day but you never get to see. Don’t forget to kiss your sweetie (it’s good luck). Take pictures if you must, but don’t try too hard unless you’re a pro. Photos never capture the full phenomenon or represent what you felt.

Third Contact

Did you miss the Diamond Ring on the way in? No worries—you’ll get a good long look during Third Contact when the moon hits the sun’s other edge before it’s time to re-don your filter glasses. The sky brightens quickly. Earth returns to normal, but you do not.

Partial Phase Two

For most, the eclipse is now OVER; folding chairs collapse and chasers beat feet to whatever conveyance brought them to the centerline. Nerds like me—the same sort of people who watch the final movie credits until the union logo—continue to drink and observe all the way to Fourth Contact.

Fourth Contact

The last tiny sliver of moon passes…passes…wait, no…okay, yes, passes finally away and bids adieu to the sun until next time. Smattering of applause.

*Note to the truly clueless: You know the moon is not actually touching the sun, right? Only the disks of the Sun and Moon as they appear in the sky are touching. Just wanted to make that clear.

Photo credit Fred Espenak

If you think you’ve seen a total solar eclipse, but aren’t sure—you haven’t.

A total solar eclipse of the Sun occurs on Earth when, during a New Moon phase, the orbit of the Moon sends it into direct alignment between the Sun and the Earth, completely blotting the disk of the Sun and casting a shadow that falls onto Earth. Those standing in that shadow witness an eclipse.

Not every New Moon produces a solar eclipse; the tilt of the Moon must be oriented exactly so with respect to Earth’s orbit around the Sun.

The width of the shadow—the path of totality—will be about 100 to 180 miles wide, and will vary based on how close the Moon happens to be from the Earth. The closer an observer stands to the center of that path, the longer the eclipse will be. The maximum length of totality is a little over seven minutes; usually they are much, much shorter. (As my husband noted after the four-minute eclipse in Egypt: “That cost a thousand dollars a minute.”)

A total solar eclipse occurs somewhere on Terra (fun fact! that’s the real name of our planet. And our moon is Luna, and the sun is Sol—no relation to the Hebrew baby name) every 18 months or so. Not all are reasonable to travel to see; many last only a few seconds and occur over a remote body of water or an inaccessible wilderness.

As far as we know, Earth (okay, I’m over it, back to the common name) is the only planet where a total solar eclipse occurs; it’s made possible because our Sun and Moon appear nearly the same size in the sky as seen from Earth. Why? The Sun’s diameter is approximately 400 times larger than the moon’s—but the Sun is also 400 times farther away.

(Think about it: Earth has one sun, one moon, and it’s possible we’re the only planet with sentient beings on it who can appreciate an eclipse. Coincidence? I think not—and that’s the subject for different blog entirely.)

Civilizations of yore had colorful, regionalized explanations for what caused an eclipse. The Chinese believed that a celestial dragon devoured the sun; Viking cultures blamed wolves. In Vietnam they believed it was a giant frog. Incan natives thought a puma god was responsible. Ancient man! So stupid.

JUST KIDDING. Superstitions continue today, though. No joke: Many 21st century citizens still consider eclipses to be an evil omen. A popular misconception in some cultures is that they’re dangerous to children and pregnant women, who hide indoors to shield themselves from totality. In India, some people fast, believing that food cooked during an eclipse will be tainted.

In a couple of countries I’ve traveled to, small children were concealed during the days surrounding the eclipse; a rumor circulated that white North American women were there to kidnap babies to take home—that was the insidious purpose of our oversized backpacks.

Some superstitions are pleasant and positive. Leave it to the Italians to plant flowers during an eclipse; everyone knows that they’ll grow to be the most colorful in the garden.