The day the sky
goes dark

A total eclipse of the heartland

The moon will pass between the sun and Earth on Aug. 21 casting a shadow that will travel across the country from coast to coast. It will be the first total eclipse over the contiguous United States in 38 years.

The eclipse path

How to view eclipse

To view the partially eclipsed sun, eye protection is required.

The solar eclipse will cut a swath across the U.S., and a narrow segment from Oregon to South Carolina will experience more than two minutes when the sun is blocked totally by the moon.

“Eclipse glasses” or hand-held viewers should meet the ISO 12312-2

international standard.

A No. 14 arc welder’s glass can be used safely to view the eclipse directly.

Simple projector

Poke a small hole in an index card with a pencil tip. Hold another card 3 to 4 feet behind in its shadow. All eclipse phases can be safely viewed on the face of the card.

Celestial alignment

As the moon orbits the Earth — traveling in tandem around the sun — it occasionally passes between the earth and the sun. Within the shadow cast on the earth, the moon is seen to block out — or eclipse —the disk of the sun, either totally or partially.

It takes light from the sun

eight minutes, 20 seconds to travel the 92.9 million miles to Earth.

Total eclipses over U.S., through 2050

A total eclipse of the sun will happen over the contiguous 48 states only four times between now and 2050. The 2017 total eclipse is the first to touch the U.S. mainland since Feb. 26, 1979.

Path of eclipse

Penumbra (partial eclipse)

Umbra

(total eclipse)

A total eclipse

of the heartland

The moon will pass between the sun and Earth on Aug. 21 casting a shadow that will travel across the country from coast to coast. It will be the first total eclipse over the contiguous United States in 38 years.

The eclipse path

The solar eclipse will cut a swath across the U.S., and a narrow segment from Oregon to South Carolina will experience more than two minutes when the sun is blocked totally by the moon.

How to view eclipse

To view the partially eclipsed sun, eye protection is required.

“Eclipse glasses” or hand-held viewers should meet the ISO 12312-2

international standard.

A No. 14 arc welder’s glass can be used safely to view the eclipse directly.

Simple projector

Poke a small hole in an index card with a pencil tip. Hold another card 3 to 4 feet behind in its shadow. All eclipse phases can be safely viewed on the face of the card.

Celestial alignment

As the moon orbits the Earth — traveling in tandem around the sun — it occasionally passes between the earth and the sun. Within the shadow cast on the earth, the moon is seen to block out — or eclipse —the disk of the sun, either totally or partially.

Path of eclipse

It takes light from the sun

eight minutes, 20 seconds to travel the 92.9 million miles to Earth.

Penumbra (partial eclipse)

Umbra

(total eclipse)

Total eclipses over U.S.,

through 2050

A total eclipse of the sun will happen over the contiguous 48 states only four times between now and 2050. The 2017 total eclipse is the first to touch the U.S. mainland since Feb. 26, 1979.