美国人准备好观看日全食

On Monday, August 21, the sun, moon and Earth will line up perfectly over many parts of the United States.

This event, called a total solar eclipse, will turn day into night for a few minutes. Then the skies will slowly lighten again.

For the first time in nearly 100 years, the total solar eclipse will be visible from the U.S. West Coast to the East Coast.

The total eclipse can be seen along a path about 110 kilometers wide and reach across 14 states.

Many areas near the main path should notice some darkness in the sky. A partial eclipse will extend up through Canada and down through Central America and the top of South America.

This eclipse is expected to be the most ever studied and celebrated.

Many places have organized events or are offering special products to celebrate the total solar eclipse. For example, you can find such products at the Eclipse Kitchen, a restaurant in Makanda, Illinois. It is selling eclipse t-shirts, safety glasses and even eclipse burgers.

Scientists are also very excited about this eclipse.

“This is a really amazing chance to just open the public’s eyes to wonder,” says Angela Des Jardins of Montana State University.

Des Jardins, a physicist, is leading an eclipse balloon project for NASA, the U.S. space agency. On August 21, students will launch balloons equipped with cameras into the sky. The cameras will send back video of the eclipse along the way.

Powerful satellites and telescopes on the ground will also be pointed at the sun and the moon’s shadow.

Astronauts will do the same with cameras on the International Space Station. Ships and airplanes will also catch the action.

Thomas Zurbuchen is the head of NASA’s science mission office. He said, “It’s going to be hard to beat, frankly."

At the same time, researchers will watch how animals and plants react to the darkness. It will be like nightfall, with temperatures expected to drop.

NASA will also present a special eclipse program on television and the internet from Charleston, South Carolina. Charleston will be the most eastern viewing point in the U.S. for the total eclipse.

The eclipse will last just 1.5 hours as the moon's shadow moves from coast to coast at speeds faster than 2,400 kilometers an hour. The sun’s crown — its normally invisible outer atmosphere known as the corona — will shine in a circle around the eclipse.

It is true that full solar eclipses happen every one, two or three years, when the moon positions itself between the sun and Earth. But they are often only visible in the middle of the ocean, or near the less-populated North or South Poles.

In no other country but the U.S. will the total eclipse be visible from one end of the country to the other. But the full path of the eclipse is much longer. It starts in the North Pacific Ocean, ends in the Atlantic, and covers 13,800 kilometers.

Twenty-one U.S. National Park locations and seven national historic trails will be in the eclipse's path.

Looking at the sun with uNPRotected eyes is always dangerous, except during the few minutes when the sun, moon and Earth are fully in line. But eye protection is needed before and after the full eclipse.

About 200 million Americans live within one day’s drive of the main path, and huge crowds are expected. Transportation officials are already warning travelers to be patient.

Kevin Van Horn is an astronomy lover from a town near Pittsburgh, Pennsylvania. He plans to make the 8.5-hour drive to Nashville, Tennessee with his wife, Cindy. Nashville is the largest city along the eclipse’s main path.

Without the trip, Van Horn noted, “It would be like going to the Super Bowl and sitting outside the stadium rather than being inside and watching it.”

But this will be the 13th total solar eclipse for Rick Fienberg, a representative of the American Astronomical Society. He will be traveling to Oregon for the event.

“Going through life without ever experiencing totality,” Fienberg said, “is like going through life without ever falling in love.”

To give everyone a chance to see the eclipse, many U.S. schools are canceling classes. And, some workplaces plan to take a break or close for the day.

I'm Alice Bryant. And I'm Bryan Lynn.

The Associated Press' Marcia Dunn reported this story. Alice Bryant adapted it for Learning English. George Grow was the editor.