Solar eclipse over the USA

January 30, 2012 By Dr. Tony Phillips
"The ring of fire:" Astrophotographer Dennis L. Mammana photographed this annular eclipse behind palm trees in January 1994. Credit: D. L. Mammana.

Mark your calendar.  On Sunday, May 20th, the sun is going to turn into a ring of fire.  It's an annular solar eclipse--the first one in the USA in almost 18 years.

An annular occurs when the Moon passes directly in front of the sun, but the lunar disk is not quite wide enough to cover the entire star.  At maximum, the Moon forms a "black hole" in the center of the sun.

The “path of annularity” is a strip about 300 km wide and thousands of km long.  It stretches from China and Japan, across the Pacific Ocean, to the middle of North America.  In the United States, the afternoon sun will become a luminous ring in places such as Medford, Oregon; Chico, California; Reno, Nevada; St. George, Utah; Albuquerque, New Mexico, and Lubbock, Texas.

This video is not supported by your browser at this time.

Outside of this relatively narrow zone, the eclipse will be partial. Observers almost everywhere west of the Mississippi will see a crescent-shaped sun as the Moon passes by off-center.

"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."

This event should not be confused with a .  In a total eclipse, the Moon covers the entire surface of the sun, bringing an eerie twilight to observers in the path of totality and revealing the sun’s ghostly corona.

"On that scale of 1 to 10," he adds, "a total eclipse is 'a million!' It's completely off the charts compared to any other astronomical event." The next total eclipse in the USA is in the year 2017.

The path of annularity cuts across the continental United States at sunset on May 20, 2012. A global map is also available.

Until then, May 20th of this year will have to do.

Annular eclipses have a special charm all their own. During an , sunbeams turn into little rings of light.  The best place to see this is on the sun-dappled ground beneath a leafy tree. Hundreds of circular shadows can be found there.

You can also make a handy solar projector by criss-crossing your fingers waffle-style. Rays of light beaming through the gaps will have the same shape as the eclipsed sun.

Be careful when looking directly at the eclipsed sun, cautions Espenak. "The ring of sunlight during annularity is blindingly bright.  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."

"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," he continues. "In western Texas around Lubbock, the sun actually sets during the annular phase."

A swollen red with a black hole in the middle?  Maybe 9 out of 10 isn’t so bad, after all.

Explore further: Cloud obscures annular eclipse

Related Stories

Cloud obscures annular eclipse

October 3, 2005

Clouds obscured an annular eclipse for most sky-gazers across Europe and Asia Monday as the moon passed in front of the sun.

Solar eclipse to be seen on January 4, 2011

December 24, 2010

Some of the world will be able to greet the first part of the new year with a solar eclipse. On the morning of Tuesday, January 4, 2011, an eclipse of the Sun will be widely visible across Europe and as far east as India. ...

Southern hemisphere to glimpse year's last solar eclipse

November 24, 2011

The tip of South Africa, Tasmania and most of New Zealand will -- weather permitting -- enjoy a partial eclipse of the Sun on Friday although the handful of hardy scientists in Antarctica will get the best view, according ...

Recommended for you

The hottest white dwarf in the Galaxy

November 25, 2015

Astronomers at the Universities of Tübingen and Potsdam have identified the hottest white dwarf ever discovered in our Galaxy. With a temperature of 250,000 degrees Celsius, this dying star at the outskirts of the Milky ...

A blue, neptune-size exoplanet around a red dwarf star

November 25, 2015

A team of astronomers have used the LCOGT network to detect light scattered by tiny particles (called Rayleigh scattering), through the atmosphere of a Neptune-size transiting exoplanet. This suggests a blue sky on this world ...

Aging star's weight loss secret revealed

November 25, 2015

A team of astronomers using ESO's Very Large Telescope has captured the most detailed images ever of the hypergiant star VY Canis Majoris. These observations show how the unexpectedly large size of the particles of dust surrounding ...


Adjust slider to filter visible comments by rank

Display comments: newest first

1 / 5 (1) Jan 30, 2012
Damn! It is missing my place by about 250 miles. BAH!
1 / 5 (2) Jan 30, 2012
Ya, no luck.
2 / 5 (4) Jan 30, 2012
I'm missing it by 400 miles. Maybe i will just drive there.
not rated yet Jan 30, 2012
Looks like I'll be making a trip to TX...
not rated yet Jan 30, 2012
If it kept going for 200 miles I'd get to see it. Lame :p
not rated yet Jan 30, 2012
My house is in the path for 2017. A total eclipse observable from our hot tub. Might head to Medford for this one, though.
3 / 5 (2) Jan 30, 2012
I wonder what will creationists say about this 'unperfect' solar eclipse.
1 / 5 (1) Jan 31, 2012
I wonder what will creationists say about this 'unperfect' solar eclipse.

What does this post have to do with creationism?

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.