An annular solar eclipse occurs when the Moon passes between the Earth and Sun, but the lunar disk does not completely block out the sun and instead leaves a "ring of fire" visible around the Moon at the point of maximum eclipse. Most anyone west of the Mississippi will see a partial eclipse, but the real treat will be for those located in the 200-mile wide path of the eclipse which will trek east from the California / Oregon border through Nevada, Utah, Arizona, New Mexico, and finally set below the horizon in west Texas. Anyone planning on looking skyward to enjoy the view will need proper eye protection, as this event should not be confused with a total solar eclipse, which occurs when the Moon covers the Sun completely during totality and is safe to watch with the naked eye.

(Click for larger image) Above: An annular solar eclipse on January 4, 2011, as photographed by Japan's Hinode satellite. People located inside the 200-mile wide eclipse track across the western United States can expect to see the same "ring of fire" on May 20, 2012, weather permitting. Photo Credit: Hinode/XRT

"I like to compare different types of eclipses on a scale of 1 to 10 as visual spectacles," says NASA's leading eclipse expert, Fred Espenak of the Goddard Space Flight Center. "If a partial eclipse is a 5 then an annular eclipse is a 9, and a total eclipse is a million!"

Annularity (the point where the eclipse is at its maximum) is expected to last over four minutes for those located on the center line of the eclipse track, with the Moon covering roughly 95% of the sun during that time. The show starts in China and Japan, with the shadow of the Moon racing across the Pacific Ocean at 1,000 mph and making landfall over the California / Oregon border shortly after 5:00pm PDT, at which point the partial phase of the eclipse will begin for those on the west coast.

(Click for larger image) Above: Map showing the path of the eclipse across the United States from the California / Oregon border to western texas. Credit: Michael Zeiler / http://www.eclipse-maps.com

Adding to the beauty of the event itself is the fact that it will occur at sunset over some of the most picturesque country the northern hemisphere has to offer - the northern California coastline, Sierra Nevada mountain range, Grand Canyon, Zion and Bryce Canyon National Parks, Meteor Crater, and Lowell Observatory are just a few popular locations for witnessing the eclipse.

Many national parks will be holding special events to celebrate the eclipse and offer the public solar observing and ranger-led programs. Local astronomy clubs will also be on hand at various locations to offer their help and knowledge. National park rangers and astronomers from the National Park Service, local astronomy clubs, and NASA scientists will all be available at several national parks with programs and hands-on eclipse activities for park visitors.

"This will be spectacular," says Jonathan Jarvis, Director of the National Park Service. "There are 33 national parks positioned for a great view of the eclipse and six parks - Redwoods National Park and Lassen Volcanic National Park, both in California; Zion National Park in Utah, Glen Canyon National Recreation Area in Arizona and Canyon De Chelly National Monument and Petroglyph National Monument, both in New Mexico - are at the center of the eclipse path."

Another 125 national parks from Alaska to western Oklahoma will offer visitors a partial view of the eclipse. "Think of Pac Man taking a bite out of the Sun," said Jarvis. "That bite will take out 55 to 80 percent of the disc of the Sun depending on where you are and that's still a very special experience."

For photographers, amateur hobbyists and professionals alike, this event has all the ingredients for providing the opportunity of a lifetime - great weather forecasts across the southwest for this time of year, sunset, and stunning vistas all add to the potential for capturing some truly incredible images. David Gonzales and his team from Project Soar will attempt to do something that no amateur astronomers have ever done before; launch cameras to the edge of space and photograph the shadow of the eclipse across the surface of the Earth.

(Click for larger image) Above: National Parks in or near the path of the eclipse. Image Credit: National Park Service

"We're planning on launching from New Mexico to catch the eclipse from the edge of space," said Gonzales earlier this week. "This will be the first time such a thing has been attempted, and to further increase the challenge the eclipse will be occurring right at sunset. We expect to reach an altitude around 100,000 feet, flying cameras running a special script on CHDK that compensates for the changing light levels while preventing blur shooting from a moving capsule."

Gonzales adds, "the cameras are insulated and chemically heated during the flight as temps drop to -50F. We fly with redundant tracking systems, one using the IDEN cell network to communicate and the other using the GlobalStar GPS system. We will be flying the Edge of Space Capsule PURSUIT; it will be the seventh for that reusable capsule, and the eighth total for our team. If we are successful, we should capture some unforgettable scenes."

"One of the unique things about this eclipse for watchers in the USA is that the Sun will still be in deep partial eclipse at sunset, making for some great photographic opportunities," said Fred Espenak. "In western Texas around Lubbock, the sun actually sets during the annular phase."

(Click for larger image) Above: A solar eclipse in March 2006, as photographed from the International Space Station over Turkey, northern Cyprus, and the Mediterranean Sea. Photo Credit: NASA

Proper eye protection is an absolute must when viewing the eclipse. Those who gaze at the eclipsed sun at any point risk a very real possibility of going blind, without feeling a thing. Even though about 95% of the sun will be covered during the point of maximum eclipse, the remaining 5% of the visible sun is still 60,000 times brighter than the full moon. "The ring of sunlight during annularity is blindingly bright," cautions Espenak. "Even though as much as 94% of the Sun's disk will be covered, you still need to use a solar filter or some type of projection technique. A #14 welder's glass is a good choice. There are also many commercially-available solar filters."

Zero-G News will be on site in Utah to bring our viewers hi-res photo and video imagery from the centerline of the eclipse path, stay tuned!

(Click for larger image) Above: An annular solar eclipse. Photo Credit: Sancho_Panza / http://www.flickr.com/photos/sancho_panza/54940367/

For details on the National Park Service and the various events being held for the eclipse, visit nature.nps.gov/features/eclipse/.

For more details on the times of the eclipse events across the United States, with detailed maps of various regions in the eclipse track, please visit Nick Anthony Fiorenza's website at www.lunarplanner.com/EGM/2012-05-20-eclipse/index.html.

Follow David Gonzales and the team at Project Soar on their quest to photograph the eclipse shadow across the the surface of the Earth from the edge of space on twitter, @davidgojr. For more information on the Project Soar team visit their website: www.mikedeep.com/Project-Soar.

NASA's eclipse website: eclipse.gsfc.nasa.gov/SEmono/ASE2012/ASE2012.html.

Detailed weather information concerning this eclipse by Jay Anderson: .www.eclipser.ca.

Detailed maps and other information by Michael Zeiler: www.eclipse-maps.com.

Visit Fred Espenak's website for a detailed guide on how to photograph the upcoming eclipse: www.mreclipse.com/SEphoto/SEphoto.html.

(Mike Killian / Zero-G News)