On Aug. 21, 2017, millions of people will witness a once-in-a-lifetime event as a total solar eclipse is visible across the United States.
A solar eclipse occurs when the moon passes directly between the Earth and the sun, causing the moon’s shadow to be cast onto the Earth.
Day will turn to night as the moon blocks out the light from the sun. Spectators may notice stars appear in the darkened sky and feel the temperature drop during the height of the eclipse.
This will be the first total solar eclipse visible in the United States since 1979; however, that eclipse was only visible in the northwestern corner of the country.
The eclipse taking place in August will be much different than the one of 1979 as it will be visible from coast to coast from Oregon to South Carolina. The most recent coast-to-coast eclipse took place nearly a century ago on June 8, 1918.
Viewing the eclipse may take some careful planning as it will only be visible in certain areas of the United States.
Poorly timed clouds may spoil the show for some spectators, even those in an ideal viewing spot, as the moon will only completely block out the sun for a few brief moments.
Where to see the total solar eclipse
People hoping to witness August’s eclipse firsthand may have to travel to view it as it will only be visible along a narrow path across the U.S.
This path, referred to as the ‘path of totality,’ is only about 70 miles wide and will stretch from Oregon to South Carolina.
Many hotels located in this path are already completely booked, so those traveling to see the eclipse may have difficulties making travel arrangements. Time is running out to make reservations with Saturday marking 100 days until the eclipse.
While this path is small, it includes five state capitals, including Salem, Oregon; Lincoln, Nebraska; Jefferson City, Missouri; Nashville, Tennessee; and Columbia, South Carolina.
Other major cities that are included in the path of totality include Casper, Wyoming; Kansas City; St. Louis; and Charleston, South Carolina.
One of the most popular towns in the country on Aug. 21 will be Hopkinsville, Kentucky, where the eclipse will last for 2 hours and 40 seconds, the longest duration of anywhere in the county.
Crowds are also expected to gather at Great Smoky Mountains National Park and Grand Teton National Park, two of the most scenic national parks in the path of totality.
Those that don’t live in the path of totality and aren’t able to travel to see the total solar eclipse will still be in for a treat as the remainder of the U.S., including Alaska and Hawaii, will still be able to view a partial solar eclipse.
Those in Canada, Central America, South America and far western Africa and Europe will also be able to witness the partial solar eclipse, weather permitting.
How to safely view the eclipse
Planning for the eclipse is more than just determining where to view it from, but also having the proper eye-wear to safely view the event.
Looking directly at the sun is unsafe except during the brief total phase of totality, when the moon entirely blocks the sun’s bright face, NASA said.
Sunglasses are not a safe option for viewing eclipses as they do not offer enough protection from the harmful rays emitted by the sun.
The only safe way to look directly at the uneclipsed or partially eclipsed sun is through special-purpose solar filters, such as eclipse glasses or hand-held solar viewers, NASA said.
Looking at the sun without eclipse glasses or a solar viewer can lead to permanent eye damage and, in some cases, blindness.
It is also important to never use solar viewers in conjunction with other devices like telescopes or binoculars as they are not designed to handle the magnification.
An eclipse can also be viewed indirectly with a pinhole camera, something that can be made with common household items.
People that miss out on the eclipse in August may have another opportunity to see one within the next decade.
On April 8, 2024, a total solar eclipse will be visible from Texas to Maine. This eclipse will be visible in cities such as Dallas; Little Rock, Arkansas; Indianapolis; Cleveland; Erie, Pennsylvania; Buffalo, New York; and Burlington, Vermont.
Some people in Mexico and Canada will also be able to witness the 2024 eclipse as the moon casts its shadow over north-central Mexico and eastern Canada.