This composite image shows the progression of a total solar eclipse over Madras, Oregon, on Monday, August 21st, 2017.  | Image: NASA / Aubrey Gemignani

Things are going to get a little wacky on April 8th, when a total solar eclipse will darken skies over North America. The Moon will line up perfectly to block the face of the Sun. Temperatures will drop around 10 degrees Fahrenheit (5 degrees Celsius). Birdsong will change from daytime to nighttime tunes. And millions of people are expected to hit the road to catch a glimpse of the spectacle.

The Verge has your guide for how to partake in the fun.

What exactly is happening? And what will I see?

“The disk of the Moon is in just the right location, just the right distance to completely cover the disk of the Sun. And when that happens, magic happens,” NASA heliophysics research and analysis lead Patrick Koehn told The Verge in an interview last October about what has shaped up to be a big year for heliophysics, or the study of the Sun and its influence on Earth and the solar system.

“When that happens, magic happens.”

Within the path of totality, aka the locations where the total eclipse will be visible on Earth, daytime will briefly look like early dawn or dusk, with light levels getting nearly as dark as night.

Just as neat, this also happens to be the only time the Sun’s outer atmosphere is visible to the unaided eye for us mere mortals on Earth. Koehn describes it as a wispy layer of high-speed gas that’s coming off the Sun. At all other times, the Sun’s own brightness obscures this corona from our vision.

How rare is this event?

“This is one of those — I won’t call it once in a lifetime, but maybe twice in a lifetime opportunities to see something like this,” Koehn says.

An even rarer type of eclipse occurred in October — a so-called “ring of fire.” That’s what happens when the Moon passes in front of the Sun while it’s at or close to its farthest point in orbit from Earth. The distance makes the Moon look smaller so that it partially blocks the face of the Sun and leaves behind what looks like a ring of fire.

On April 8th, the Moon will be close enough to Earth to completely blot out the Sun. After next week, there won’t be another total solar eclipse visible from the contiguous US for another two decades until August 23rd, 2044. The last time something like this happened here was on August 21st, 2017. But the path of totality was much narrower then, meaning many more people should be able to see the upcoming total eclipse.

This time around, the Moon will be closer to the Earth than it was last time — creating a wider path of totality that encompasses more densely populated areas. That path will reach between 108 and 122 miles wide next week, giving some 31.6 million people a view from where they live. That’s compared to around 12 million people who lived within the 62 to 71-mile-wide path of totality in 2017.

Where and when can I see the eclipse?

This particular eclipse will begin over the South Pacific Ocean before reaching land at Mazatlán on Mexico’s Pacific coast around 11:07AM PT. From there, it will continue its path over the country before crossing into the US and slicing a diagonal path across 15 states from Texas to Maine. It’ll pass over Canada east of the Great Lakes, with its last stop on the Atlantic coast of Newfoundland before leaving the continent behind at 5:16PM NT.

Image: NASA
The path of totality and partial contours crossing the US for the 2024 total solar eclipse occurring on April 8th, 2024.

NASA has a helpful “Eclipse Explorer” map tool and more information on its website about when the total eclipse will be visible from location to location. People in some regions outside the path of totality will still be able to see a partial eclipse, which the Eclipse Explorer also explains. Weather will also come into play, and clouds could unfortunately rob some places of good view even if they’re in the path of totality. The New York Times has a forecast tool to see how much cloud cover there could be in your area during the eclipse.

Wherever you are while viewing it, you’ll see it happen in phases, from a partial eclipse to totality when the Moon completely blocks the Sun. Totality lasts 4 minutes and 28 seconds at most, enduring the longest around Torreón, Mexico, and ranging between 3.5 and 4 minutes in other locations.

What safety precautions should I take?

Be warned, you can burn your retina “pretty badly and almost instantaneously” by looking directly at the Sun, Koehn tells us. Totality, those few minutes when the Sun is completely blocked by the Moon, is the only time that risk disappears. During this brief reprieve, NASA says viewers can look at the eclipse without any special eye protection. BUT — and this is a big but — protection is necessary immediately before and after the eclipse reaches totality because looking at a partial eclipse can still damage your eyes.

Heed these wise words from NASA:

Even when 99% of the Sun’s surface (the photosphere) is obscured during the partial phases of a solar eclipse, the remaining crescent Sun is still intense enough to cause a retinal burn. Note, there are no pain receptors in the retina so your retina can be damaged even before you realize it, and by then it can be too late to save your vision!

Another important warning: sunglasses are no help. They can even put you at more risk because they allow your pupils to get bigger, letting in more damaging solar radiation. You’ll need specially designed solar eclipse glasses for a partial eclipse. The American Astronomical Society has a list of reliable suppliers. Notably, it does NOT recommend buying the cheapest glasses from online marketplaces like Amazon. It’s best to make sure the seller is listed on its list of reliable suppliers before making a purchase online, the American Astronomical Society says.

As an alternative, you can also craft a makeshift pinhole camera at home using paper or cardstock, tape, and aluminum foil (NASA has instructions online).

Where can I watch the solar eclipse online?

NASA will livestream the event starting at 1PM ET. You can watch on the agency’s website or the NASA Plus streaming service. It’ll also have Spanish-language coverage on YouTube.

Read More – The Verge – Spaces