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.
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.
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.
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.
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