NASA estimates that 32 million Americans will travel along the path of totality in San Antonio, Dallas, Little Rock, Indianapolis, Cleveland, Buffalo and Burlington, Vt., on August 21, 2017, from the Oregon coast to South Carolina.
This eclipse will be the longest on Earth since at least 2009 and may be the most widely seen in history. What's more, it comes during peak magnetic perturbation on the Sun, which is quite striking during totality, assuming you have a clear sky.
Here's an overview of what you'll see in hours, minutes and seconds.
Scientists refer to “first contact” as the moment when the moon hits the sun's disk — or when the partial phase of the eclipse begins. For those on the path to perfection, it's one to two hours to perfection.
A minute or two after first contact, you'll see the Moon begin to occupy the right side of the Sun. The only way you'll notice is with eclipse glasses. Look up when the partial eclipse begins in your location; Note that while only those in a roughly 115-mile-wide path from Texas to Maine will see the total eclipse, a partial eclipse will be visible across the lower 48 states.
60 to 15 minutes in total
Unless you're wearing eclipse glasses, you won't notice much at first. But in the next 45 minutes, you will be able to see the Moon's eclipse of the Sun increase. At first it will be a pain. Then a bite. Then there will be only one crescent.
Within about 15 minutes of totality, the changes in your surroundings will be very noticeable. Seventy to 80 percent of the sun will be obscured, and the landscape will be dimly lit. It might resemble an old western-style movie like the sepia filter on your phone. The color may appear slightly off, like the sun shining through a pane of smoked glass. You may feel a general sense of unease or foreboding.
The temperature will start to drop. You can also see most of the white, puffy cumulus clouds pulsating due to heat loss from the sun.
You may first start thinking, “I need a vest” or “It's getting cold.” As totality approaches, temperatures may drop 10 to 12 degrees if the air is dry and crisp, or 5 to 8 degrees if humid.
At the same time, shadows appear sharp. During a solar eclipse, the Sun's apparent size shrinks, meaning shadows fall from a smaller source. As a result, the shadows become sharper, because the rays of light – and therefore the shadows – overlap more.
You may also notice small sickle-shaped projections of the eclipsing Sun, often in the shadows of leaves and trees; Each small gap or opening acts as a small “pinhole projector”.
At this point, it will start to feel strange outside. The sun will see As if it were shining in the sky – indeed it was – but only at 20 percent of its usual intensity. Crickets start chirping. Birds may return to their roosts.
90 seconds before total
In another minute and a half, things start to happen faster – and the environment changes before your eyes. There are several things to note:
The Moon covers almost the entire Sun, and the Sun appears to shrink into a point of light. This means that the last rays of sunlight we see are perfectly parallel and aligned, or collimated.
However, atmospheric turbulence (air pockets, temperature differences, etc.) can bend or refract parallel rays at slightly different angles. Now the misaligned rays will create a strange interference pattern on the ground. It is reminiscent of the shadowy waves that ripple across the floor of swimming pools. If you have a piece of white paper, paper, or poster board, bring it and place it on the floor. This will make it easier to observe shadow bands.
Shadow bands first appear about 90 seconds before totality, and are most noticeable between 60 seconds and 30 seconds into totality. They can also be seen in post-total moments.
Look southwest about 90 seconds before totality. The sky is purple or hazy as if a veil of darkness is hanging over the head. The rest of the sky is normal.
You'll see the edge of the umbra, the darkest part of the Moon's shadow, coming at several times the speed of sound. When the shadow crosses from Mexico to Texas, it moves at 1,600 mph. By the time it reaches northern Maine 68 minutes later, it will be moving at 3,000 mph.
The sky can suddenly turn dark faster than you can imagine. Every time you blink, you open your eyes to a different landscape. Your eyes may struggle to adjust at first. The stars wake up from their midday slumber, suddenly becoming noticeable and twinkling overhead. Jupiter emerges above and to the left of the Sun; Venus, and possibly Saturn and Mars, appear in the lower right.
Eventually, the sky sinks into the deepest shade of royal blue you've ever seen. It's hard to describe. The air is quickly cooled by the moon's shadow, and as it sinks the air slackens or subsides—suppressing any breeze that may have previously stirred up. It is also possible to change the wind direction.
You should still be wearing glasses. Be on the lookout for “Bailey's Bells,” the end points of sunlight shining through the valleys of the moon. They last about 15 seconds or so before coming to fullness.
And then the diamond ring – the countless beads all frozen into a single singularity, becoming a beacon.
you can only Remove your eclipse glasses during totality. When you do, you'll be transported to another universe (metaphorically speaking, of course).
where is the sun want Stay and you will see a black hole. This is the blackest color you've ever seen. That's why the moon blocks all incoming light.
Fanning out from behind the Moon is the Sun's active, diaphanous atmosphere—the corona. Hair-like filaments of the magnet are visible extending outwards.
The horizon in all directions glows in a soft shade of amber, dubbed the “360 Degree Sunrise.” Remember that the moon's shadow is only 100 to 120 miles wide, so the horizon depicts areas that still enjoy daylight. You are in the middle of a localized night that only you can experience.
Savor every moment of totality. Put the phones away – they don't capture the eclipse. Instead, treasure every moment. Time seems to stand still, but that moment is gone in a second. However, memories last a lifetime.
