by The total solar eclipse that will cross a large chunk of the continental US on Monday, along with parts of Mexico and Canada, will be one of the most spectacular celestial events in recent memory. Here’s what you need to know:
What is a total solar eclipse?
The phenomenon occurs when the moon moves in front of the sun, and blocks its face completely, creating a bright sky that darkens to twilight in just seconds. The path of totality, which will be about 115 miles wide for Monday’s eclipse and will sweep across 15 US states in a northeasterly direction, from Texas to Maine, for about an hour, is called the moon’s shadow track. starting at 1.30pm CT and ending at approximately 3.35pm ET.
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How rare is it?
The most recent total solar eclipse in the US was in 2017, but an interval of just seven years is unusual. The previous one happened in 1979, and the next one won’t be visible in the contiguous US until August 2044. Only 16 other total solar eclipses have occurred over at least part of the lower 48 states in the past 155 years.
Did we just have a solar eclipse?
The spectacular “ring of fire” show last October was something called an annular solar eclipse, which occurs when the moon moves directly in front of the sun, but is at or near its farthest point from Earth, and as that is not big enough to cover the whole envelope. the face of the sun. You can find NASA’s guide to the different types of eclipses here.
Why is this one special?
An estimated 31.6 million people, almost three times as many as in 2017, are living in the path of totality – which is longer, and also wider than almost every other total eclipse before, because the moon is closer to the Earth and that she loses a wider shadow. . The time of totality in any given location is also longer. Seven years ago, the longest run anywhere was two minutes and 42 seconds. On Monday, it will be four minutes and 28 seconds in Torreón, Mexico, and almost everywhere on the course can expect three and a half to four minutes overall.
How can I watch it?
If you live anywhere in the path of totality, or can travel to it, congratulations, you have a front seat. Remember that you need eclipse glasses (more on that in a minute) to look up at all times except for the few minutes of a total eclipse. But everyone in North America outside the path should be able to see at least a partial eclipse of varying percentages, and NASA will be live streaming the entire event here. Here’s the caveat: longer-range weather forecasts call for rain and clouds in many areas of the southern and central US on Monday, so the best viewing may be in the east.
And here’s NASA’s Eclipse Explorer, where you can enter any US address or zip code to see what will be visible from that location.
What can I expect to see?
You can find NASA’s guide to the phases of a total solar eclipse here. First contact is when the outer edge of the moon appears to touch the sun for the first time, creating the beginning of a partial eclipse and the crescent sun diminishing in size to totality (second contact). In the moments before totality, look for (in order) umbra bands, Baily’s Beads and a diamond ring, three of the most significant phases of a total eclipse.
Shadow bands, NASA says, are fast-moving, long, dark bands separated by white spaces that can be seen on the sides of buildings or the ground just before totality; Baily’s Beads are ephemeral rays of light from the sun creeping through the valleys along the moon’s horizon, and give way to the diamond ring effect, the last, single spot of bright light just before the end of all direct light.
Related: ‘You see one, you want to see them all’: 105-year-old excited for her 13th solar eclipse
The sun’s corona, the outermost part of its atmosphere, can only be seen during the total part of the eclipse, then, after totality, the same effects return. For most places, the partial eclipse phase lasts from 70-80 minutes, according to NASA.
How can I watch safely?
To look at the eclipse directly, you need special eclipse glasses. Regular sunglasses, frosted or tinted glass, or any other method that lacks the necessary eye protection won’t cut it. NASA’s must-read eclipse safety guide says: “Looking at any part of the bright sun through a camera lens, binoculars, or telescope without a special purpose solar filter secured over the front of the optic will cause immediate eye damage. ” Don’t do what Donald Trump did in 2017.
Many stores, businesses, schools and libraries still offer free or low-cost glasses (Google is your friend here), but you need to make sure they have a safety rating. The American Astronomical Society warned last month that unsafe fakes and counterfeits were in circulation, and published a handy list of suppliers of safe (ISO 12312-2 compliant) viewers and filters.
Experts advise against taking photos of the eclipse with a mobile phone (unless it is protected by a solar filter) as it could damage the camera. NASA has ideas here.
What if I don’t have eclipse glasses?
You can make a box pin projector by following the steps in this video, courtesy of NASA’s Goddard space flight center. An even simpler way is to use anything with a small hole, like a kitchen colander, to project an image onto the ground. And remember that many places all over the country, like science centers and zoos, will be hosting special eclipse events so you can watch the action safely.
