'MURICA — NASA has issued a set of safety guidelines ahead of a solar eclipse that will be visible to more than 300 million people in the United States next month. <br /> <br />The Great American Eclipse 2017 can be viewed directly through special-purpose solar filters, such as eclipse glasses or a handheld solar viewer, according to the NASA website. <br /> <br />These filters should meet ISO safety standards and the manufacturer's name and address should printed on the product. <br /> <br />Do not use filters that are more than three years old, or that have scratched or wrinkled lenses. Do not use regular sunglasses or homemade filters. <br /> <br />An alternative method is to use a pinhole projector. Simply cut a pencil-sized hole in a piece of paper or cardboard then stream the sunlight through the hole onto a makeshift screen, such as a piece of paper. <br /> <br />The eclipse will start in Oregon on August 21 and pass over 12 states before exiting in South Carolina. Its path will be 67 miles wide.
