On August 21, 2017, a solar eclipse will be visible across a section the continental United States, coast to coast, for the first time since 1918.
A solar eclipse occurs when the Moon passes between the viewer on Earth and the sun, completely—and perfectly—blocking out the full diameter of the sun. During this event, if you are within the path of totality (the shadow of the eclipse), the sky darkens and you will be able to see the solar corona, the extended atmosphere of the sun made up of plasma and reaching millions of miles beyond the part of the sun that is normally invisible to us. This is, by all accounts, a spectacular and life-changing event. Anywhere else in the country, outside the path of this shadow, you will see partial phases of the eclipse. And while I’ve not yet personally seen one, I have nearly blinded myself observing the sun, so using precautions when viewing the eclipse is critical.
WHERE TO GO
If you plan on viewing the total eclipse, you will need to head to a part of the country where the 70-mile wide shadow will cross the continent. It will enter the US on the Oregon coast, then sweep across the country, exiting in South Carolina. A complete map of the eclipse path can be found here. NASA also has a website up for this event.
TIMING AND EXPERIENCE
If you are in the path of totality, the eclipse begins in Oregon at 10:15 Pacific Daylight
Time, and ends on the shores of South Carolina 94 minutes later. As the shadow approaches your location, you will see an increasingly large portion of the sun darkened by the mass of the Moon. A few moments before totality, you may see the shadow moving towards you across the landscape from the west as it rapidly approaches at a speed of between 2400 mph in Oregon to 1500 mph in South Carolina. As totality begins, just before the sun is completely covered by the Moon, you will see bright points of light along the edge of the disk called “Baily’s Beads.” These are bits of sunlight skimming through valleys and crevices in the lunar surface, and last for just a few seconds. Then—totality. At the centerline of the Moon’s shadow, this phase will last for about two minutes, to two minutes, forty seconds, depending on your location. At this time, the sky will be dark as late twilight—animals will react to what they perceive as sunset, temperatures will drop, and wind may blow as the air mass around you becomes colder. The solar corona will be visible and brighter stars will appear. Steve Fentress, director of the Strasenburgh Planetarium in Rochester, New York, and author of the new astronomy book “Sky to Space,” says that there will be other things to look at during this time: “During totality in this eclipse, the sky should become dark enough for Jupiter to be seen off to the Sun's lower left and Venus to the upper right.” Both will add to the spectacle.