Everything you need to know about the 2024 solar eclipse

Today, millions of people will gather to marvel at the total solar eclipse.

The awe that eclipses inspire is profound. “You suddenly feel as though you can see the clockwork of the solar system. Where you think you lived doesn’t look like the same place anymore,” Ernie Wright, who creates data visualizations and eclipse maps for NASA, told Vox.

Total solar eclipses like the one crossing America today are beautiful, but they’re fleeting. Totality, when the sun is completely covered by the moon, lasts just a few minutes. And the whole thing — from the start of the partial eclipse to the end — takes just a few hours. The experience is sublime, but it’ll leave you wanting more.

Here’s the good news: Total solar eclipses happen somewhere in the world about every 18 months. That’s how long it takes for the specific conditions that create eclipses (the phases of the moon, the distance of the moon to Earth, and the moon crossing the plane of Earth’s orbit) to line back up.

As the moon passes in front of the sun on April 8, its shadow will knock down solar power production in a sweeping band across the United States from Texas to Maine, home to more than 31 million people.

The United States currently has more than 139 gigawatts of solar electricity generation capacity. That’s more than two and a half times the amount of solar that was on the grid during the last total eclipse in 2017. The upcoming eclipse will also shade a path twice as wide as the last one. Though much of the country will see some decline in solar power production, the biggest decrease will be directly under the moon’s shadow.

The biggest US travel event of this year might not be Taylor Swift’s sold-out concert tour or a long-awaited March Madness face-off.

Instead, it could well be the upcoming solar eclipse on April 8, which could see as many as 4 million people in the US journeying to view it. This year’s total solar eclipse is particularly special for the US: Although the phenomenon happens globally every 18 months, this one will be visible across a huge swath of the country, making witnessing it more accessible. Plus, the eclipse is expected to last longer than the prior one did in 2017, adding to its allure.

On Monday, April 8, millions of people will get to see the Great North American Eclipse. Most people on the continent will see a partial solar eclipse, the sun gradually getting smaller as the moon passes in front of it.

But if you’re in exactly the right place — along the narrow path of totality that runs from Mexico to Indianapolis to Montreal — the moon is going to line up directly in front of the sun and completely block it out.

When the total solar eclipse comes to the United States on April 8, there is one rule you must remember: Never stare directly into the sun. Even when the sun is partially obscured by the moon, its rays are still strong enough to permanently damage your eyesight. The only time to look upon the eclipse without glasses is when the sun is fully covered by the moon during totality, which only will last three or four minutes, depending where you are. If you are not in the narrow path of the totality, spanning from Texas to Maine in the United States, this will not be an option for you.

To look at the sun during the eclipse’s partial phase, you either have to find some eclipse glasses, or use an indirect method — like a pinhole projector (more on that below) — to view the eclipse. Because if you don’t, you risk permanent eye damage.

There’s a total solar eclipse somewhere on Earth once every 18 months or so. And whether it’s passing over a barren, ice-cragged coast of Antarctica, a remote African desert, or a lonely patch of ocean, you can be sure there will be an umbraphile — a shadow-loving eclipse chaser — there to see it.

Eclipse chasers are people who plan their lives around (and spend small fortunes on) eclipse travel. This year, of course, they’ll be joining millions of people in the United States to see the total solar eclipse on April 8.

The English word eclipse comes from the Greek ἔκλειψις, ekleípō: disappearance, abandonment. A solar eclipse is the moment in which the sun disappears, abandoning the world. It’s like being forsaken by a god.

The ancient Greeks thought of a solar eclipse as an act of abandonment, a terrible crisis and an existential threat. It meant that the king would fall, that terrible misfortunes would rain down on the world, or that demons had swallowed the sun.

On August 21, the moon will completely block out the sun over a 60-mile-wide path stretching from Oregon to South Carolina. The rest of the country will experience a partial version of this, with the moon blocking 50 percent of the sun or more.

It’s a rare celestial event, and a great excuse to step outside in the summer and get a glimpse of the stars in the middle of the day. But it will be thrilling for reasons that go beyond anomaly. People who have seen total eclipses say the experience moves them deeply and existentially.