Total Solar Eclipse 2017
August 21, 2017
A solar eclipse occurs when the moon passes between the sun and Earth, blocking all or part of the sun. On August 21, 2017, all of North America will experience a partial solar eclipse that will last two to three hours. Certain parts of the United States will witness a total solar eclipse.
Solar Eclipse Viewing Path
You will be able to view a partial solar eclipse from anywhere in North America. Halfway through the eclipse — during the phase known as totality — the moon will completely block the sun's bright face for a couple of minutes. Day will turn into night, and the sun's outer atmosphere will become visible.
To see a total solar eclipse you must be within the path of totality, which is a ribbon about 70 miles wide that will cross the U.S. from west to east. The first point of contact will be at Lincoln Beach, Oregon, at 9:05 a.m. PT. The total eclipse will end near Charleston, South Carolina, at 2:48 p.m. ET. The longest duration of totality will be near Carbondale, Illinois, where the sun will be completely covered for two minutes and 40 seconds.
Solar Viewing Safety
Looking directly at the sun is unsafe except during the brief phase of totality during a solar eclipse when the moon entirely blocks the sun, which will happen only within the path of totality.
The single safe way to look directly at the uneclipsed or partially eclipsed sun is through approved solar filters, such as eclipse glasses or handheld solar viewers. Homemade filters or regular sunglasses are not safe for looking at the sun.
NASA recently adopted a new, more stringent ISO safety standard to better protect your eyes from harmful solar radiation. When shopping for a product for safe solar viewing, look for a label on the package that says "ISO 12312-2, Filters for Direct Observation of the Sun."
Be sure to follow these guidelines:
- Always inspect your solar filter before use, and discard it if it's scratched or damaged.
- Read and follow any instructions that come with your solar viewing product.
- Always look away from the sun while putting on or taking off your solar viewing apparatus to prevent yourself from looking directly at the sun.
- Do not look at the uneclipsed or partially eclipsed sun through an unfiltered camera, telescope, binoculars or any other device; and do not look through an unfiltered device while using eclipse glasses or a solar viewer, as the concentrated solar rays will damage the filter and enter your eye(s), causing injury.
- If you're within the path of totality, you can remove your solar viewing device only when the moon completely covers the sun's bright face and it suddenly gets dark.
- As soon as the bright sun begins to reappear, you must put your solar viewing equipment back on to watch the remaining partial phases of the eclipse.