Utahns who braved the early hours to watch Saturday morning's Perseid meteor shower discovered a rare treat: a spectacular display of the northern lights.
The spooky, gorgeous light show — called by scientists the aurora borealis — was visible for about an hour starting 4 a.m. The huge display was the result of the sun's ejecting a mass of gasses from its corona a few days before.
This is the period of "solar maximum," the part of the sunspot cycle reached about every 11 years when the sun is most active. At such times it releases explosive bubbles of material from its corona.
When the coronal mass strikes Earth's atmosphere, electrical interactions between it and the atoms of the atmosphere cause an ionization glow, often in the form of sheets or curtains. Usually this is visible only in the regions near the poles, such as Alaska or Antarctica.
But this time the solar eruption was so powerful that auroras were visible as far south as Los Angeles, according to NASA.
Here are three reports by Utahns who witnessed Saturday morning's display.
This reporter: I drove to Knolls, Tooele County, about 90 miles west of Salt Lake City, hoping to photograph the meteor shower. I mounted my camera on my telescope, which tracked the stars so that a long exposure would not cause the stars to streak.
When the nearly full moon set about 4 a.m., the difference was almost as dramatic as if someone had turned out a light. Suddenly, I was able to see constellations that had been washed out by brilliant moonlight.
I noticed a ghostly pillar of light in the heavens to the north and I soon began wondering if it could be an aurora borealis. Suddenly, columns of light showed up above the horizon, generally to the north. They formed the brighter "folds" of a curtain of light, which slowly flowed toward the east. Often it was most intense to the north-northeast.
It was indeed an aurora, the most dramatic I've ever seen.
Parts would fade and disappear, others brighten. It reminded me of a nimbus, as in the rays of a halo. The light had the texture and softness of a candle flame.
At its greatest extent, it was about 85 degrees across and reached to 35 degrees above the horizon, with a bottom of the curtain of light about five degrees above ground.
One segment or another would suddenly brighten and intensify, as if a light were shining on the outer folds of a hanging curtain. When it was brightest it seemed to flicker. Once it looked like the first hint of dawn except that it was northerly.
The color seemed gray or slightly green. Large gaps often showed between light pillars.
But photos I took that were exposed for several minutes show dazzling purple, green, orange, white and pink tints, and color that I could not see with my naked eye appears between the pillars. Stars shone through the display.
I watched spellbound, taking photos, paying little attention to the occasional meteor that would fizz and blaze to the upper right. The aurora dimmed about 4:27 a.m., then brightened to its greatest show, lighter than the Milky Way.
About 4:45 p.m. it became more diffuse and faded. It was basically gone about 17 minutes later.
Dr. Keith N. Finlayson, a Salt Lake physician who is an experienced astrophotographer: "I got up this morning to watch the Perseid meteors and got some really good photos of the aurora borealis instead . . .
"From the Salt Lake Valley (it showed) really good detail, some nice curtains on the aurora, purples and reds."
David J. Parker, North Bountiful, went outside to watch the Perseids and discovered the display of the northern lights, which he watched between 4 and 5 a.m.
"It was pretty much like a vertical curtain of lights. The colors were pastel but a good display," he said.
"It was wonderful. I should have called more people than I did."
Parker noted that he has never seen the aurora borealis this far south. However, he added, "You could see stars trough the northern lights. That is a good sign that they were, in fact, the northern lights."
NASA reported on Saturday, "Observers in dark-sky areas across Canada and much of the United States were treated to the unusual spectacle of meteors seen against a backdrop of colorful northern lights.
"Auroras were spotted as far south as Los Angeles, Calif."
The space agency posted information about the display, which it said might reappear early this morning, at the Internet site spaceweather.com.
E-mail: bau@desnews.com