Solar Eclipse 2017

Everything you need to know about the total solar eclipse coming August 21, 2017

This image of the moon crossing in front of the sun was captured on Jan. 30, 2014 by NASA's Solar Dynamics Observatory observing an eclipse from its vantage point in space.

Photo by NASA

Solar eclipse 2017—are you ready for it? On August 21, 2017, for the first time in 99 years, a total eclipse of the sun will pass across the entire continental United States. 

The Solar Eclipse

In the animation from which this still was taken, the Earth, moon, sun, and shadow cones are viewed through a telescopic lens on a virtual camera located far behind the Earth. Long focal lengths like the one used here appear to compress the distance between near and far objects. Despite appearances, the geometry of the scene is correct. The moon's umbra cone is roughly 30 Earth diameters long, barely enough to reach the Earth, while the sun is almost 400 times farther away.

Image & caption by NASA's Scientific Visualization Studio

The path of the eclipse—and the shadow of the moon—will cut directly through the center of America, tracing a path coast to coast from the Pacific to Atlantic from Oregon to South Carolina. A total of 14 states will be able to get a direct view of the unprecedented celestial event. About 12 million people live along the 2,500 mile (4,000km) umbral path of the moon. Another 200 million people live within a day's drive, which is leading some officials to speculate on possible traffic nightmares on that day. All of North America will be able to experience a partial eclipse at a minimum. The eclipse will begin in Oregon at about 10:15 PDT, and end off the coast of South Carolina just before 3 pm EDT.

It's been almost four decades since the continental United States has seen a total solar eclipse. The last time occurred on February 26, 1979, and was only visible from five states along the Pacific Northwest and into the Northern Plains region.

When the moon passes directly between the Earth and Sun, temporarily blocking the Sun, there will be about two minutes of darkness for those living within the direct path of the moon's shadow. The sun's corona or atmosphere will be visible as a glow around a dark center. 

The Science of the Sun

One of a series of photographs of the eclipse of the Sun which was taken from the Apollo 12 spacecrft during its transearth journey home from the Moon. This view was created when the Earth moved directly between the Sun and the Apollo 12 spacecraft.

Image & caption by NASA

NASA is planning on using no less than 11 spacecrafts to capture a stream of images while the event is in progress. Along with the spacecraft, images will be collected by three NASA aircrafts, dozens of high-altitude balloons, and the ISS or International Space Station.

Among other things, heliophysicists will be making observations on how the solar eclipse affects the weather.

Safe Viewing

The danger to your eyesight from an eclipse is real. It is not safe to look directly at the eclipse—even a partial solar eclipse. There are glasses with solar filters, or special viewers made for an eclipse. A pinhole projector, which uses a tiny hole to allow sunlight in, and a reflecting system, is an alternative. Normal sunglasses, no matter how dark, don't provide adequate protection.

The only time it is safe to view the eclipse directly is within the 70 mile wide area that will experience the total eclipse—and only during the two minutes or so of the complete dark of the moon.

Anyone can watch the event on NASA Television, with live coverage and multiple views of the eclipse, interactive features and more, here

Now Reading
Solar Eclipse 2017
Read Next
Sci-Fi Movies Influenced by 'Dune'