A total solar eclipse will happen on August 21, 2017 and this will be seen across continental United States. Experts have determined the exact places where skywatchers will be able to completely view the eclipse and the best place for the greatest duration. This is the first total solar eclipse that will darken the U.S. since February 26, 1979.

Deemed as the "Greatest American Total Solar Eclipse," the event will be seen completely from Oregon to South Carolina, Space.com reported. An area has been determined called the "path of totality" which is actually a narrow stretch of land measuring about 70 miles or 113 kilometers wide. This is a rare opportunity for skywatchers, says experts, because this is the first time that the path of totality is entirely on land. Most of the time this narrow path is found along oceans and seas since the Earth is mostly covered with water.

The NASA Eclipse Web Site posted an interactive Google Map that shows the point of Greatest Eclipse (GE) and the point of Greatest Duration (GD). Skygazers can use this map to effectively find the best spot to view the total solar eclipse but experts say that viewers can be hundreds of miles from the theoretical GD and still enjoy a good view. However, this may only last for a few seconds.

Astronomers also recommend to watch and listen for local weather forecasts for the area with GE to get a chance to see the total solar eclipse with only a few clouds in the sky. In Oregon, where a portion of the narrow path of totality can be found, the eclipse will only be seen for about 2 minutes.

NASA also reminds eclipse viewers to consider the effects of valleys and mountains found along the surface of the moon. These lunar land formations or lunar limb profile could change the eclipse durations and contact times by 1 to 3 seconds and therefor the GD could also change by about 10 to 20 kilometers.

Furthermore, experts advise that no matter where a skygazer is in the U.S., he has to use eye-protection filters at all times while viewing the eclipse. It is predicted that the rest of the areas in the U.S. that are not in the GE and GD could still have 55 percent partial eclipse to view on August 21.