The sunset on May 20 promises to be a spectacular one.
The earth, moon and sun will align, causing an eclipse.
Starting at about 6:20 p.m. the moon will move in front of the sun, causing an annular solar eclipse, often called a ring of fire eclipse, in southwestern Utah.
Along the Wasatch Front, people can see a deep partial eclipse, which will cause the sun to look like a crescent, said Seth Jarvis, director of the Clark Planetarium.
The sun will be in full "annularity" when the moon best covers the sun for about four minutes at 7:31 p.m. as viewed from a vantage with a low horizon between Cedar City and St. George, according to Patrick Wiggins, NASA/Jet Propulsion Laboratory solar system ambassador to Utah.
Such an eclipse can occur multiple times a year, but it can only be seenfrom a small portion of the planet. The last annular eclipse visible from the United States was in January 1994, and the next one won't happen until Oct. 14, 2023, Wiggins said.
The eclipse happens only during a new moon, when the illuminated side of the moon is facing away from the Earth. It doesn't happen frequently because the moon's orbit is tilted, so it is often below or above the Earth, said Dave Bernson, president of the Salt Lake Astronomical Society.
The difference between an annular eclipse and a full eclipse depends on how far from Earth the moon is as it makes its elliptical orbit, Bernson said. When the moon is farther, it blocks only about 90 percent of the sun, causing an annular eclipse.
Eye burn • It's a delightful sight, but this ring of fire will indeed burn, burn, burn if viewers don't have proper eye protection.
"You've got to use something made specifically for looking at the sun," Wiggins said. "If you burn out your eyes, you can't go to Walmart and buy new ones."
Regular or polarized sun glasses won't cut it. They may make the sun seem less bright but don't stop the infrared and ultraviolet rays that can burn out a person's retina in just seconds.
"The part of the eyes that are injured don't have pain receptors, so it won't hurt, but you'll go blind," the planetarium's Jarvis said. "It's called solar retinopathy, and it burns out retinal cells. I've talked with plenty of people who looked at the sun and now can't see in the center of their vision, only peripherally."
The cardboard-framed glasses from an eye doctor, which can look similar to eclipse viewers, don't work either.
Those who want to see it simply need to buy eclipse viewers from the Clark Planetarium, the Leonardo or the Natural History Museum of Utah for about $2. For those closer to Tooele, the Copy Cottage (500 E. Village Blvd. #101) in the stargazing community of Stansbury Park, also is selling them.
People also can purchase #14 grade or higher welder's glass to look through. However, it can be difficult to find, and using two #7 pieces stacked on top of each other won't work.
Those using a pair of binoculars or a telescope also need to buy filters that will allow them to see the sun safely. Those are available at the Clark Planetarium, and cost around $100.
"I tell people if they can't view it correctly, don't view it at all," Wiggins said. "It's not worth the permanent damage that will occur."
Sweet spot • The eclipse path's center line the spot from which the moon most fully and centrally covers the sun, causing the ring-of-fire effect goes right through the tiny town of Kanarraville, located right off Interstate 15 between St. George and Cedar City.
"It's one of the few places in the world right on the center line, especially in North America," said Bonnie Char Oldroyd, public relations specialist with the Cedar City/Brian Head Tourism Bureau, which is calling Kanarraville the "sweet spot" to view the eclipse. "What better way to see Southern Utah and see the eclipse in the beautiful, scenic area of Kanarraville?"
The hamlet of about 300 has no restaurants, gas stations or public restrooms, but the tourism bureau is carting in scores of portable toilets and food vendors will be on hand to sell food and drinks.The bureau also is providing maps highlighting areas to view the eclipse.
People travel the globe to see eclipses, and thousands could descend on the area to view this one.
The town of Newcastle is about 40 miles west of City Cedar and is also right on the center line, but it's farther off of Interstate 15. Brian Head resort will have a ski lift open and other mountain locations, if the snow is melted, will be possibilities.
"The die-hards will want to be on the center line, but the view difference from Cedar City and St. George won't be noticeable," Oldroyd said.
People in northern Utahcan still see a partial eclipse, making it look like a Pac-Man is eating the sun. The sun will turn to a bright crescent, causing essentially two twilights as the light grows dim at the eclipse peak, followed by sunset about an hour later.
Those who want to see the effect of the eclipse without directly looking at it can do so by creating a pinhole viewer, but the image will be quite small. The planetarium, the astronomical society and other groups are setting up several viewing sites, from Weber State University to the Gateway Mall to Dimple Dell Recreation Center in Sandy, Jarvis said.
Wiggins, though, urges people to make the trip to southern Utah.
"You can drive four hours or wait until 2023. It's worth the drive."
Venus transit • About two weeks after the eclipse on June 5 the sun also will offer a once-in-a-lifetime performance.
On that Tuesday, from about 4 p.m. to sunset, Venus will make a transit across the sun.
The last time such an event was viewable from Utah was 1882, and it won't be visible again from the Beehive State until 2125, decades after even Halley's Comet will have come and gone again.
Venus' transit is caused by a celestial alignment similar to that in the eclipse. Venus follows an orbit tilted to the Earth and the sun, but once every 100-plus years, the orbit aligns so viewers on Earth can see Venus cross the face of the sun twice in eight years. The last one was in 2004, but was visible only from Europe and Asia.
The first recorded transit was in 1639, just about a quarter-century after the first telescope was made.
Members of the Salt Lake Astronomical Society will gather June 5 at the Natural History Museum of Utah with solar telescopes to allow the public to view the transit.
Those with good eyesight and, of course, proper eye protection can look at the sun without magnification and likely can see a small, dark spot moving across the sun. However, it may be difficult for some to see, and solar telescopes will provide a better view.
Salt Lake City viewing locations:
The Gateway Mall fountain, 450 W. South Temple
Salt Lake Library Square, 200 E. 500 South
University of Utah South Physics Observatory, 125 S. 1400 East
Salt Lake County
Dimple Dell Recreation Center, 10600 S. 1000 East in Sandy
Weber State University observatory, 1551 Edvalson St. in Ogden
"Sweet spot" is Spring Creek Road, the primary viewing site until full
Discovery Park/Cedar Middle School
West of Cedar City:
Parowan Gap: Program, including a guided tour of lunar petroglyphs and a short hike to equinox Kairn, will begin at 7 p.m. at the Kiosk
Mountain locations (pending access):
Brian Head Peak
Brian Head Resort Giant Steps $8 for Sky Lift Ride (weather permitting)
Point Supreme Cedar Breaks National Monument (no services)
The following parks will have programs and activities about the eclipse:
Natural Bridges National Monument
Speakers will discuss why the annular eclipse occurs and how to safely view it. Safety viewing glasses for the following day's event will be distributed for free and activities range from decorating cookies to learning about the phases of the moon to building mini rockets.
When • 11 a.m. to 3 p.m. Saturday, May 19
Where • Aquatic Center at the Hills, 2090 W. Royal Hunter Drive, Cedar City
Cost • Free