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Sky-gazers across North America in your treatment on April 8 when a total solar eclipse will pass over Mexico, the United States and Canada.
The event will be visible to millions – including 32 million people in the United States alone – who live along the path the moon’s shadow travels during the eclipse, known as the path of totality. For those in areas that experience totality, the moon’s shadow will completely cover the sun. Those in the center line of the path will see an eclipse that will last between 3½ and 4 minutes, according to NASA.
The next total solar eclipse won’t be visible across the contiguous United States again until August 2044. (It’s been more than six years since the “Great American Eclipse” of 2017.) And an annular eclipse won’t be visible across the this part of the world again until 2046.
Here’s everything you need to know about the upcoming eclipse.
What is a total solar eclipse?
A total solar eclipse occurs when the moon passes between the Earth and the sun, completely blocking the face of the sun.
Those within the path of totality, or locations where the moon’s shadow will completely cover the sun, will see a total solar eclipse. People outside the path of totality will still be able to see a partial solar eclipse, where the moon only blocks part of the sun’s face.
During a total solar eclipse, the sky will be as dark as dawn or dusk, and astronomers can expect different stages of the eclipse.
The moon suddenly becomes invisible between the Earth and the sun – the event begins with a partial eclipse in which the moon appears to be rising from the sun, making the sun appear like a crescent. Depending on your location, the partial eclipse may last between 70 and 80 minutes, according to NASA.
When the moon begins to cross in front of the sun, the star’s rays will settle around valleys on the moon’s horizon, creating blobs of moonlight around the moon in a phenomenon known as Baily’s beads.
As totality approaches, Baily’s beads will quickly disappear until a single point of light remains, like a giant glistening diamond ring.
The diamond ring will disappear when totality comes, and there is no longer any sign of sunlight. Stars or bright planets may shine in the dark sky, and the air temperature will drop as the sun disappears. The sudden darkness makes animals quiet.
The chromosphere, or part of the sun’s atmosphere, may glow in a thin pink circle around the moon during totality, and the sun’s hot outer atmosphere, or corona, will appear as a white light.
As the moon continues across the face of the sun, the diamond ring and Baily’s beads and the partial solar eclipse will be visible on the opposite side of the moon to the sun. reappears completely.
Where can I see the eclipse?
The total solar eclipse will be visible in parts of Mexico, Canada and more than 10 US states, and a partial crescent-shaped solar eclipse is expected to be visible in 49 states – weather permitting.
The eclipse will first appear over the South Pacific and begin its journey across North America. The first full stop on the path is the Pacific coast of Mexico, expected at 11:07 a.m. PT (2:07 p.m. ET).
The path will continue across Texas, Oklahoma, Arkansas, Missouri, Illinois, Kentucky, Indiana, Ohio, Pennsylvania, New York, Vermont, New Hampshire and Maine. Then, it will cross Canada in southern Ontario, Quebec, New Brunswick, Prince Edward Island and Nova Scotia, ending on the Atlantic coast of Newfoundland at 5:16 pm (3:46 pm ET).
Use our interactive map to see what the eclipse will look like from your viewing location.
How can I watch the eclipse safely?
The only time it is safe to see the sun without eye protection is during a “total” total solar eclipse, or the short hours when the moon completely blocks the sunlight and the sunlight is not visible , according to NASA.
Otherwise, wear ISO 12312-2 certified eclipse glasses or use a handheld solar viewer before and after total, and always during a partial eclipse.
Separately, you can observe the sun with a telescope, binoculars or a camera with a special solar filter on the front, which functions in the same way as eclipse glasses would.
Staring directly at the sun can cause blindness or impaired vision. During the 2017 total solar eclipse, a young woman was diagnosed with solar retinopathy, retinal damage from exposure to solar radiation, in both eyes after viewing the eclipse with what doctors believed were eclipse glasses not held up to safety standards. There is no treatment for solar retinopathy. It may improve or worsen, but it is a permanent condition.
Sunglasses will not work as a substitute for eclipse glasses or solar viewers, which are 100,000 times darker and held to an international safety standard.
The lenses of the eclipse sunglasses are made of a black polymer, or resin infused with carbon particles, which blocks almost all visible, infrared and ultraviolet light, according to The Planetary Society. Sunglasses do not block infrared radiation.
For safe manufacturers and resellers of eclipse glasses and filters for optical devices, including cameras and smartphones, check the list maintained by the American Astronomical Society.
Put on your eclipse glasses before you look up and remember to look away from the sun before you take them off again. Always keep an eye on any children wearing eclipse glasses to make sure they don’t remove them while looking at the sun.
If you normally wear glasses, keep them on and put eclipse glasses over them or hold a handheld viewer in front of them, according to the American Astronomical Society.
Do not look at the sun through any unfiltered optical device — camera lens, telescope, binoculars — while wearing eclipse glasses or using a handheld solar viewer, according to NASA.
Sun rays can still burn through the filter on the glasses or the viewer, given how thick they can be through an optical device, and can cause serious eye damage.
If you bought eclipse glasses to view the “ring of fire”, save your eclipse glasses and your viewer for the total solar eclipse in April by storing them at room temperature in an envelope or in their original packaging to avoid scratches.
What can we learn from eclipses
Eclipses allow scientists to study the sun and how it interacts with Earth in unique ways, and NASA has selected several projects to fund during a total solar eclipse.
“Scientists have long used solar eclipses to make scientific discoveries,” NASA program scientist Kelly Korreck said in a statement. “They helped us make the first detection of helium, gave us evidence of the theory of general relativity, and allowed us to better understand the influence of the sun on the Earth’s upper atmosphere.”
One project will rely on NASA’s high-altitude research planes to take images of the eclipse from 50,000 feet (15,240 meters) above Earth’s surface to capture never-before-seen details in the sun’s corona. The images could also help scientists search for asteroids orbiting near the sun.
Amateur radio operators will experiment during both annular and total solar eclipses to see how these phenomena change the way radio waves travel. Operators in different locations will record the strength of their signals and how far they travel. Scientists are interested in tracking this distance because the sun directly affects the Earth’s upper atmosphere, or ionosphere, which allows radio communications to travel further. But when the moon blocks the sun, that can change.
Scientists and citizen scientists alike plan to observe the most active regions of the sun and the passing moon using the Goldstone Apple Valley Radio Telescope during both eclipses.
The sun is approaching solar maximum later this year, and scientists are eager to capture this peak of activity through a variety of observations that can only occur during eclipses.
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