A once-in-a-lifetime opportunity: Everything you need to know about the upcoming total solar eclipse in the US on April 8, 2024

Sure! Here is an article covering everything you need to know about the upcoming total solar eclipse on April 8, 2024:

The Sky Will Go Dark: The Total Solar Eclipse Of 2024

On April 8, 2024, millions of Americans will be able to see a rare celestial occurrence: a total solar eclipse. It's going to be awesome. If you're in the center of the moon's shadow, known as the totality, the sky will go dark for a few minutes in the middle of the day. The temperature will drop, stars will appear, and birds will become confused and start chirping their nighttime songs. And it's all because of a cosmic coincidence: From the Earth, the moon and the sun appear to be roughly the same size.

It's Going To Be Epic

By many measures, April's event will (please excuse the pun) eclipse the last total solar eclipse that passed over the United States in 2017. There are few reasons. The shadow of totality will be twice as wide as that of the 2017 eclipse (more on why below), so it will be easier to find a place to view it in any given state. The time of totality — how long the moon is completely covering the sun — will also be almost twice as long, at over four minutes in many locations. "And I think even more importantly," says Ernie Wright, who works in NASA's Scientific Visualization Studio. "2024 passes over a much bigger population," he says. "More than twice as many people actually live in the path and don't have to go anywhere to see it." If you live anywhere in the path from Kerrville, Texas, to Houlton, Maine, you're in luck. If you want to travel to see it, book accommodations now! Hotels in many areas are filling up. But even if you can't get to the path of totality, you'll be able to view at least a partial solar eclipse (which is pretty cool) from any location in the lower 48 United States. It will be the last total solar eclipse in the lower 48 United States until 2045. So, if you've been eager to see one in the US, now is your last chance for 21 years.

Why Do We Have Solar Eclipses?

There's a simple answer: The moon occasionally covers the sun in its path across the sky. But it's more complicated than that. Three cosmic conditions have to be met to produce the shadow. First, there has to be a new moon. One side of the moon is always lit by the sun, but the lit side isn't always facing the Earth. This is how we get the phases of the moon. During a solar eclipse, the dark side of the moon must be facing the Earth. Ernie Wright/NASA Then, the moon has to cross the plane of Earth's orbit. If the dark side of the moon has to be facing the Earth for a solar eclipse to occur, why don't we have them every new moon? The moon's orbit isn't perfectly matched up with the Earth's.

The Three Conditions Of A Solar Eclipse

That's because the moon is tilted on a 5-degree axis. No one is completely sure why the moon is slightly skewed, but it might have to do with how it was likely formed: from a massive object smashing into Earth. A depiction of the a new moon's shadow missing the Earth. NASA Then, the moon has to cross the plane of Earth's orbit. If the dark side of the moon has to be facing the Earth for a solar eclipse to occur, why don't we have them every new moon? The moon's orbit isn't perfectly matched up with the Earth's. That's because the moon is tilted on a 5-degree axis. No one is completely sure why the moon is slightly skewed, but it might have to do with how it was likely formed: from a massive object smashing into Earth. A depiction of the a new moon's shadow missing the Earth. NASA Finally, whether the entire sun is covered depends on the moon's distance to the Earth. You might remember this from middle school science: The moon's orbit around the Earth is not a perfect circle. It's an ellipse.

How Do We Know When Eclipses Will Happen?

The three conditions that conspire to create eclipses — the new moon, the moon crossing the plane of Earth's orbit, and the moon's distance to the Earth — all recur on slightly different time scales. It takes the moon 27.212 days to return to a node (this is called a draconic month). Every 27.554 days, the moon returns to its closest approach to Earth (an anomalistic month). The moon finishes cycling through all its phases once every 29.530 days (a synodic month). The system that keeps track of all three months and when they overlap is called the Saros cycle, and it predicts both solar and lunar eclipses. Saros is ancient: The Babylonians discovered it in the few centuries before the start of the common era. And they worked it all out just by making careful observations of the moon for hundreds of years. Today, NASA doesn't have to rely on the Saros cycle alone to predict eclipses. "It starts with knowing where the Earth, the moon, and the sun are," Wright says of making eclipse prediction and maps. "But then you need to calculate, based on the geometry, what the shape of that shadow is and where it's going to hit the Earth."

The Path