The total solar eclipse is around the corner in Texas. Here’s what to know.

For the first time in over a century, Central Texas will plunge into near total darkness — in the middle of the day.

Next Monday, April 8, a total solar eclipse is coming to a swath of land encompassing the Texas Hill Country, San Antonio, Dallas and other parts of Texas.  A partial solar eclipse will form over Houston about midday. In Central Texas, there hasn’t been a total solar eclipse – when the moon completely covers the sun – since 1878, and in North America since 2017.

In Houston, however, the last time the city experienced a total solar eclipse was in 1286. And the next time won’t be until the year 2200. Which is why Angela Speck, the chair of the Department of Physics and Astronomy at the University of Texas at San Antonio, said if Houstonians have the chance to see the full eclipse, they should make the journey to Central Texas.

“An eclipse is just one of those things that you should see if you get the chance,” Speck said. “There’s nothing else like it. Only totality will do that. The partial eclipse in Houston just isn’t enough.”

The Earth’s orbit around the sun isn’t perfectly aligned with the moon’s orbit around the Earth. Because of this, the Earth only gets a perfect alignment of the sun and moon twice a year, but even so, those alignments don’t always add up to a total eclipse, said Speck.

On average, Earth gets an actual perfect alignment every 18 months or so, and at any given spot on Earth, total solar eclipses only happen once every 375 years. However, like in Houston, these intervals can be even longer than that.

What to expect during a solar eclipse

The longest duration of darkness for this eclipse is 4 minutes and 30 seconds, which will occur in spots in the Hill Country and around Dallas. In San Antonio, the times will vary, but at the UTSA campus it will be 2 minutes and 25 seconds.

The exact timing the eclipse will take place depends on location. For example, in Dallas, the eclipse will begin at 12:23 pm with totality starting at 1:40 pm. In Houston, the eclipse will be at 94.2 percent of the total eclipse. It will start at 12:20 pm and end at 3:01 pm with the fullest coverage at 1:40 pm.

Onlookers in Texas might not be able to see the eclipse in detail. Weather forecasters say clouds will likely block the view of the eclipse . If there’s a break in the cloudy weather, only the outermost ring of the sun, called the corona, will be visible once the moon completely covers it.

When that happens, the temperature will dip and animals may begin to act strangely.

“Lots of animals react, some go to sleep, some wake up and some do unexpected things,” Speck said. “Birds often swarm or flock in the 10 to 15 minutes before darkness hits and they may make a lot of noise, like they do on a normal day after sunset.”

Once plunged into total darkness, the birds will go totally quiet. In one case, in 2017, the Galapagos tortoises at the South Carolina Zoo – animals that usually don’t do anything active – all started breeding.

During the total eclipse, people can take off their eclipse glasses, but only when they are absolutely certain the sun is totally hidden. The sun is 100,000 to a million times brighter than the corona or the full moon, so even with a 0.1 percent of the sun showing, it is too much for the human eye.

Which means people viewing the eclipse in Houston cannot take their eclipse glasses off at any point. But in Hill Country, San Antonio or places in the direct eclipse path, people can remove their glasses.

The same goes with taking photos of the eclipse. During a partial eclipse, someone can try to take a photo through the solar eclipse glasses, but during the total eclipse, decent phones should be able to capture the corona.

What happens if you look at the solar eclipse?

Looking at the sun directly during a partial solar eclipse can cause permanent and irreversible damage to your eyes.

“If you only look at the sun for just a second, you get these spots that form in your vision, but that spot generally goes away with time,” said Timothy McCulley, professor and chair of ophthalmology at UTHealth Houston. “But if you look at the sun even longer, it can become permanent and it will never go away.”

The sun will literally burn a hole into your retina, so McCulley said it’s important to get proper and official eclipse-glasses to wear. This means the glasses should have the international standard ISO 12312-2. Anything else could be fake.

Earlier this year, the American Astronomical Society warned eclipse viewers of the potential of fake glasses. People can test their glasses at home, however, before viewing the eclipse. Viewers should not be able to see anything except for very bright lights – which should appear faint through the lens. If anything else is visible – such as your bookcase or pictures on the wall – then the glasses are not dark enough for solar viewing.

The AAS shared a list of verified vendors.

If a person does not have the proper eclipse glasses, they can also make a cardboard pinhole project which uses the reflection of the sun to demonstrate the eclipse.

Definitely do not look at the eclipse with binoculars or a telescope without eye protection, McCulley said. The sun’s strength will only be heightened, like burning an ant with a magnifying glass. Sunglasses, or a pile of sunglasses on top of each other, also does not work.

“Whatever the time it takes to permanently damage your retina is, the sunglasses may give you slight extra time, but it’d be a completely impractical number of sunglasses to make that happen,” McCulley said. “Just use the eclipse glasses and make sure they work.”

Where to get free eclipse glasses?

In Houston, residents can grab some free eclipse glasses at select Houston public libraries, such as Looscan at Willowick Road and the Jungman Neighborhood Library on Westheimer.

Other places will sell them in stores, such as H-E-B, Walmart, Buc-ee’s, 7-Eleven and even Cracker Barrel. To see the full list, you can check out the American Astronomer’s Society website .

Houstonains can also grab their glasses at events hosted throughout the city. The Space Center Houston will have a viewing party with complimentary glasses, and the Houston Museum of Natural Science will host one as well.