Surely you’ve heard by now about what will happen on Aug. 21: a total solar eclipse, with its path crossing the United States from Oregon to South Carolina.

But it’s likely you learned this information after Cameron Hummels did.

Hummels started planning his Aug. 21 trip way back in 2009, right after he was dazzled by seeing a total solar eclipse in China.

“It’s one of nature’s spectacles, like the aurora (borealis) or the northern lights or volcanoes or some of these really amazing natural phenomena,” Hummels, a researcher at Caltech in Pasadena and an astronomer, said. “With an eclipse, at least you know when it’s going to happen.”

Hummels will drive up to Fossil, Oregon, a tiny town with a population of less than 500 people. That’s where a friend has a farm, right in the path of the total eclipse. He’ll camp out with about 100 others and is planning lectures and events for any eclipse fans who show up.

Nik Arkimovich, an amateur astronomer and volunteer at Mount Wilson Observatory in Los Angeles, started planning his trip to see the eclipse along its “path of totality” 10 months ago.

“Actually, I was a latecomer,” Arkimovich said. The tour group of about 250 people that he and his wife wanted to join had already booked up. But they lucked out when a few others canceled. Now, they’ll head to Casper, Wyoming, all for the few minutes of the stellar event.

“I can’t oversell this,” Arkimovich said. “It is the most spectacular celestial phenomenon you can possibly witness.”

All for a moment

So, just what will happen on Aug. 21? The moon will move between the Earth and the sun, blocking out part of the sun in some areas and all of it along a 70-mile-wide path across the United States. The effect of the sun being totally blocked will last less than three minutes.

“It’s difficult to see a solar eclipse, because you have to be on the right spot on the Earth when it’s happening,” said David Reitzel, astronomical lecturer at Griffith Park Observatory in Los Angeles.

“That’s why people are so excited about this one, is that it’s crossing the entire United States and virtually everybody is within one day’s drive.

“They’re calling it the ‘Great American Eclipse,’ ” Reitzel said. That’s because it’s all ours: (The total eclipse will) be viewable from the United States only.

For the uninitiated, those who have seen total solar eclipses tell of all sorts of weird phenomena, in addition to a darkened sky. Crickets start chirping and some birds start singing, thinking it’s nighttime. A shadow moves across the sky, starting at the horizon. Stars, Mercury and Venus are visible in the middle of the day. The air will cool.

Unfortunately, we’ll experience none of that in Southern California.

The “path of totality,” where the sun will be completely blocked, is a long day’s drive from Los Angeles.

Many places have long been booked along the eclipse’s path, people told the Southern California News Group. There are even reports that some hotel operators have canceled long-standing reservations to cash in on higher-paying customers once they learned they were in the perfect spot for Aug. 21. If you haven’t made plans, you could get in the car the day of, but it’s a risk, Reitzel said.

“People can still go within 100 (or) 200 miles of it and then wake up super-early in the morning and then drive,” Reitzel said. “So you can get up at 5 in the morning and then drive, although they’re worried about eclipse traffic as well.” You might end up sitting in a traffic jam.

But the effects will still be viewable in Southern California, and there are places to see them. Almost 70 percent of the sun will be covered, when viewed from here.

Griffith Park Observatory is sure to be very crowded, Reitzel said. The facility invites people to see the event on the lawn with eclipse-viewing glasses and telescopes. Inside, the observatory’s coelostat device will show the coverage of the sun. Caltech will have solar telescopes and eclipse glasses for people to use and astronomers on hand to explain the event.

You can see the effects of the eclipse anywhere with sunlight. With proper viewing glasses, like ones with a NASA rating, you’ll be able to look at the sun and see a crescent shape as the moon moves in front of it. With a homemade pinhole-and-paper setup, you’ll be able to see that shape projected onto a piece of paper. And if there are dapples of sunlight, such as filtering through tree branches, those will be crescent-shaped.

Some pricey shade

Though it’s a once-in-a-lifetime event for most people, this will actually be Arkimovich’s second total solar eclipse. He, his wife and a friend traveled to Easter Island — no easy place to reach — for a total eclipse in 2010.

“There are real eclipse junkies,” he said. “These are people who travel wherever the moon’s shadow touches the ground.”

He doesn’t count himself among them, even though he and his wife calculated the per-minute price of their Easter Island trip. For the chance to see the four-and-a-half-minute event, “we paid about $2,500 a minute (each) to stand in some really neat shade.”

Total solar eclipses aren’t as rare as you might think, but the last time one was visible (a partial eclipse) from Los Angeles was 1979, when the path of total blocking of the sun crossed the Northwestern states. The year 1918 was the last time the path of totality crossed the contiguous United States. And the last time the path of totality crossed Los Angeles? That was 1724, before L.A. became L.A., according to the scientists at Griffith Observatory.

Though most eclipse fans he knows are traveling for the big day, Thomas Meneghini, executive director at Mount Wilson Observatory, altruistically volunteered to stay behind in Los Angeles to host viewings at the facility. He’ll hand out eclipse glasses and may also rig a projection from one of the observatory’s telescopes.

“Somebody’s got to stay at the helm,” he joked. “I’m the director, so I should be the last man off the boat, anyway.”

But for those who made plans years in advance and have spent a lot of money for an event that lasts just a moment, he said, “it’s all worth it.”