Read more: Planned eclipse gatherings and events
SALT LAKE CITY — Excitement is building over a rare astronomical opportunity in Utah Sunday.
If the skies stay clear, millions of people along the Wasatch Front will have a chance to see an eclipse of the sun early Sunday evening.
"We do expect huge crowds" at organized viewing areas, said Seth Jarvis, director of the Clark Planetarium. "People are going to want to see this."
In southwestern Utah, T-shirts are already on sale promoting that area as "The Sweet Spot" for the eclipse. For several minutes starting at around 7:30 p.m. Sunday, observers in the Cedar City area will see a "ring of fire" around the moon as the eclipse reaches its maximum.
Northern Utah sky-gazers will see only a crescent of fire, not a circle.
"This is your chance to see a rare celestial wonder," Jarvis said.
Unlike a total eclipse in which the moon completely blocks the sun, this time the sun will not be completely hidden. In a so-called "annular" eclipse, the moon is slightly farther away from the earth. From prime viewing areas, a small portion of the sun will shine in a perfect circle around a silhouette of the moon.
Veteran eclipse watcher Joe Bauman of Salt Lake City said the view will be impressive but it may be disappointing for those who have experienced the day-turning-to-night drama of a total eclipse.
"Yes, it's going to be very interesting," Bauman said. "It's going to be something that you'll remember and treasure and like a lot. But it's not quite the same as seeing a total" eclipse.
The gift shop at Clark Planetarium has already sold more than 10,000 pairs of "eclipse glasses" which make it possible to safely observe the sun without damage to the eyes.
Kanarraville is 'Sweet Spot'
The eclipse track, the path the moon's shadow will trace on the earth, runs across the Pacific Ocean. When it reaches Northern California it runs in a straight line east-southeast to Albuquerque. In Utah, it crosses I-15 at Kanarraville, just south of Cedar City.
Officials there started planning two years ago for the possibility of sizeable crowds this weekend. The town of 400 people ordered portable toilets to accommodate 5,000. Food vendors will be on-site and the Iron County Sheriff will have a command post at Kanarraville's designated viewing area.
Kanarraville mayor Keith Williams said it's a privilege to host a solar eclipse. "We haven't had a lot of things happen here, you know," Williams said. "So, yeah, I think it's good even though it's overwhelming to people in town."
Many eclipse buffs are expected to avoid possible crowds in Kanarraville and watch the eclipse from a highway near the Utah-Nevada border. By a coincidence of geography, the eclipse track is precisely aligned with a 25-mile stretch of state Route 56 between Newcastle and Modena. Anywhere on that 25-mile stretch is considered a "sweet spot" for the eclipse.
Science organizations have established at least six designated viewing areas. They are at Weber State University, the University of Utah physics building, Library Square, Gateway Mall, Sam's Club in Murray and Dimple Dell Recreation Center in Sandy. At each location, there will be telescopes equipped with solar filters and experts to answer questions.
From the Wasatch Front, the eclipse will look off-center. The moon will cover 90 percent of the sun, leaving a fiery crescent of the sun exposed to view.
Is it worth driving to southern Utah to see a perfect circle of fire?
"Depends on whether or not you want to see something really spectacular, or something that's just really pretty cool," Jarvis said.
Eclipse buff Patrick Wiggins, who's been designated a "Solar System Ambassador to Utah" by NASA and who once chartered a Boeing 737 to take him and other enthusiasts to view an eclipse in Mexico, said eclipses of the sun stir unusual feelings in many observers.
"Eclipses of the sun — there's just something weird about them," Wiggins said. "The human psyche is just not used to watching the sun disappear in the daytime."
Wiggins and Bauman have each traveled to total solar eclipses in five locations around the world. Bauman saw his only annular eclipse in New Mexico in 1994 and observed a perfect ring of fire. "It's a shocking thing," Bauman said. "I enjoyed it a lot."
View with eye protection
Proper viewing of an eclipse requires eye protection. The risk is that direct sunlight can burn the retina in seconds leading to partial, or even total, blindness.
"It's not like the sun is more dangerous during an eclipse," Jarvis said. "It's not. It's always dangerous. It's just that now you're going to be tempted to look at it because the moon's moving in front of it."
To avoid eye damage, observers are urged to buy cheap "eclipse glasses" for about $2. No. 14 welding glass will protect the eyes, but according to Jarvis, normal welding glass is not safe. Solar filters are available for binoculars, telescopes and other lenses. Those on a budget can construct a pinhole-projector made from a cardboard box; it projects a small image of the sun onto a piece of paper.
"Sunglasses are not acceptable," Wiggins said. "You need these things that are made specifically for looking at the sun." He recommends the cheap eclipse glasses. "You can't worry about fashion sense or whatever," Wiggins said. "You're going to look geeky. But wear them."
In southern Utah, Brian Head Ski Resort plans to start up a ski lift on Sunday, to give visitors a ride to a prime high-altitude viewing area. The Giant Steps Sky Lift costs $8 for a round trip. The lift will open at 5:30 p.m.
Area resident Mike Saemisch said he plans to go by snowmobile to the top of Brian Head Peak.
"You won't have another chance to see it," Saemisch said. "And with our normally clear weather, and great views, it should be very spectacular."
Copyright 2015, Deseret News Publishing Company