The percent of sun coverage and the path of totality across the United States during the solar eclipse. (NASA)

There’s no shortage of great resources to learn about the highly anticipated total solar eclipse happening on Aug. 21 (now just a few days away!). We’ve discussed what to expect both here in Washington and other parts of the country.

If you’re just starting to tune in, or are still looking for a visual guide to the eclipse at your viewing location, a couple of sites stand above the pack.

One is this 3-D eclipse Web application, developed by NASA’s Jet Propulsion Laboratory. It allows you to run simulations of the eclipse by clicking any location on Earth. A nice feature about NASA’s app is that it shows the perspective of the eclipse from space. By moving your cursor, you can track the path of the moon’s shadow (both the darker umbra and lighter penumbra) as it races across North America.


(NASA Jet Propulsion Laboratory)

If you’re looking for something more streamlined with a more Earth-centric view of the sky, timeanddate.com is another great resource.

Capital Weather Gang's Angela Fritz explains what could happen to your eyes if you were to watch the Aug. 21 eclipse without special sunglasses and how to spot the ones that work. (Claritza Jimenez,Daron Taylor,Angela Fritz/The Washington Post)

The Norway-based company is a repository of information on various timekeeping- and astronomy-related topics, including Monday’s solar eclipse. Live animations give a minute-by-minute play of how the eclipse will unfold in hundreds of cities and towns across the country. Just enter your location in the search box, and you can watch how the moon’s shadow will track across the sun, as well as start and end times of each phase of the eclipse.

How and why the moon’s path across the sun varies

If you’re an astronomy geek like myself, you’ve probably noticed that the track of the moon’s shadow across the face of the sun differs depending on your location. For example, in Salem, Ore., and Charleston, S.C. — two cities in the path of totality — the moon will approach and move away from the sun at different angles when the eclipse starts and ends.

Moon position with respect to the sun 30 minutes after the solar eclipse begins in Salem, Ore. and Charleston, S.C. (timeanddate.com; used with permission)

Eclipse watchers in Salem will see the moon take a nearly straight-line path across the sun in an up-down, northeast-southwest trajectory. In Charleston, however, the moon will approach the sun from the upper to center-right and swing down across the solar disk in a U-shaped path.

What causes the shape and angle of the moon’s trajectory across the sun to differ by location? It’s not the easiest thing to visualize, but it’s mainly influenced by your latitude (how far north or south you are from the path of the moon’s shadow), as well as the sun’s height and position in the sky with respect to Earth’s horizon when the eclipse begins.

If you’re not lucky enough to watch the eclipse from within the 70-mile path of totality, the orientation of the moon’s maximum sun coverage also depends on your latitude and where the sun appears in the sky with respect to Earth’s horizon throughout the eclipse.

Generally speaking, here’s what to expect:

  • The greater your distance from the path of totality, the less the sun will be covered — and the shorter the duration of the partial eclipse from start to finish.
  • If you’re north of the path of totality, the moon covers the lower portion of the sun’s disk, while the upper rim remains exposed.
  • If you’re south of the path of totality, the moon covers more of the upper portion of the sun. In the western United States, cities south of the path of totality will typically see the upper and left half of the sun obscured.

Here’s how the eclipse will unfold in 10 major cities

Below are several images and links to live animations that show how the solar eclipse will progress in Washington and nine other cities across the Lower 48 — including two in the path of totality.

If you’re looking for your specific viewing location not listed below, you’ll probably find it find it here. Note from the graphics that “direction” indicates the compass-based orientation of the sun in the sky during each phase of the eclipse, while “altitude” is the sun’s height above the horizon. All times shown are local.

Washington, D.C.

In D.C., the partial solar eclipse begins at 1:17 p.m. The moon will approach the right-hand edge of the sun, then pivot around the center of the sun’s disk. The peak of the eclipse arrives at 2:42 p.m., when 81.1 percent of the sun will be obscured. The eclipse ends as the moon leaves the sun’s center-left edge at 4:01 p.m.

Seattle

Seattle lies just north of the path of totality, so residents will see a partial solar eclipse. When the eclipse starts at 9:08 a.m., the moon will approach the upper-right-hand edge of the sun. It will then pivot around the center of the sun’s disk, leaving a crescent of the sun exposed. At the peak of the eclipse (10:20 a.m.), 91.8 percent of the sun will be obscured. The eclipse ends when the moon leaves the sun’s lower left edge at 11:38 a.m.

Phoenix

In Phoenix, the partial solar eclipse begins at 9:13 a.m. The moon will sink down across the sun’s upper edge from nearly straight above, then slide down to cover the center-left portion of the solar disk. At 10:33 a.m. the eclipse reaches its peak, with 63.1 percent of the sun obscured. As the eclipse ends at noon, the moon’s shadow will depart the center and lower-left portion of the sun’s edge.

If you’re looking for Los Angeles on this list, note that the eclipse in Phoenix will closely resemble how it appears in Los Angeles. The main difference is that in Los Angeles, the sun will be about 1 percent less obscured. In L.A., the eclipse starts eight minutes earlier and the maximum eclipse occurs at 10:21 a.m.

St. Louis

St. Louis is tricky. I’ve included it because many people assume the city will see a total solar eclipse, when in fact, the difference between seeing a partial vs. total eclipse will be a matter of mere miles from the city center. Maps from NASA show the path of totality will pass just south of the Gateway City. Note how the graphic for St. Louis doesn’t mention the “full eclipse” phase, as shown with Nashville and Charleston further down this list.

St. Louis residents debating whether it’s worth driving a few extra miles to see 100 percent coverage vs. only 99 percent, consider this: Even though 99 percent sounds impressive, that 1 percent difference in coverage will have an enormous difference on how dark the sky gets. At 99 percent obscuration, the sun will still be 10,000 times brighter than it would be in the path of totality where the sun is 100 percent obscured.

Chicago

Chicago will see a partial solar eclipse, beginning at 11:54 a.m. The moon will approach the upper-right-hand edge of the sun, then slowly rotate around the center of the sun’s disk. The peak of the eclipse arrives at 1:19 p.m., when 86.8 percent of the sun will be obscured — the upper rim of the sun’s disk remaining visible. The eclipse ends as the moon leaves the sun’s center-left edge at 2:42 p.m.

Nashville

Nashville will have the privilege of witnessing a total solar eclipse. The partial eclipse begins at 11:58 a.m., as the moon starts to drift over the upper-right portion of the sun’s disk. Totality begins at 1:27 p.m. and will last one minute and 59 seconds. At that time, viewers will be able to see the sun’s corona, or outer atmosphere. As the eclipse progresses, the sun will gradually reappear from right to left. It ends when the moon’s shadow exits the center and upper-right portion of the sun’s disk at 2:54 p.m.

Atlanta

Atlanta lies about 60 miles south of the path of totality, so residents there won’t see a total solar eclipse. The eclipse begins at 1:05 p.m., and throughout the event the moon will take a U-shaped path across the sun’s disk, similar to Nashville and Charleston. But because Atlanta lies outside the path of totality, a small crescent of the sun’s lower disk will remain visible when the eclipse peaks at 2:36 p.m. The maximum sun coverage will be 97.1 percent, which will be a sight to behold, but not quite the full experience. As the eclipse ends at 4:01 p.m., the moon will be seen leaving the upper-left edge of the sun.

Charleston, S.C.

Assuming the weather cooperates, Charleston will be the only city to witness a total solar eclipse on the East Coast. When the eclipse begins at 1:16 p.m., the moon will drift over the upper-right portion of the sun’s disk. Totality begins at 2:47 p.m. and will last one minute and 38 seconds. As the eclipse continues, the sun will reappear from right to left. The eclipse ends when the moon departs the center/upper-left portion of the sun’s disk at 4:09 p.m.

New York City

In New York, the partial solar eclipse begins at 1:23 p.m. The moon will approach the right-hand edge of the sun, and then pivot around the center of the sun’s disk. The peak of the eclipse arrives at 2:44 p.m., when 71.4 percent of the sun will be obscured. The eclipse ends as the moon leaves the sun’s left edge at 4 p.m.

Miami

In Miami, the moon’s shadow will begin to cross the upper-right portion of the sun at 1:26 p.m. The moon will approach the upper-right edge of the sun, then pivot around the center of the sun’s disk. At the peak of the eclipse (2:58 p.m.), 78.3 percent of the sun will be obscured. The eclipse ends as the moon leaves the sun’s upper-left edge at 4:20 p.m.

Don’t see your city listed? Search more locations here.

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Link: More eclipse coverage from The Washington Post