SAFFORD, Ariz. -- Firefighters widened a defensive ring around a mountaintop observatory yesterday to try to hold back two wildfires and protect one of the world's most powerful telescopes, which is under construction.
Crews used bulldozers and fire retardant around Mount Graham International Observatory, which has two operating telescopes and the $120 million soon-to-be-completed Large Binocular Telescope. The ground crews were helped by an air tanker plane dropping retardant.
"The building's not going to burn, but the smoke and heat could do some real damage to the instruments inside," said Pruett Small, a fire official.
Researchers from around the world use the observatory, which is an extension of the University of Arizona. When fully operational in 2005, the Large Binocular Telescope will be the world's most technologically advanced optical telescope. It is expected to yield images nearly 10 times sharper than those from the Hubble Space Telescope.
The telescope will be able to take images of planets outside the solar system for the first time, Powell said.
The observatory is on 8 acres of pine forest on Mount Graham's 10,470-foot Emerald Peak. It has a sprinkler system that officials said would be turned on if flames come within a quarter-mile.
Only Arizona's summer rains will be able to put out the wildfires, officials said.
One of the fires was a lightning-sparked blaze that had grown to more than 6,200 acres by early yesterday. It was burning less than a mile southeast of the observatory. A blaze about 3 miles northwest that had grown to more than 6,500 acres prompted the evacuation of the observatory and 85 cabins on the mountain Friday.
No homes were immediately threatened by the fires, which were expected to join within the next few days.
"I can't hardly stand it to think there's a fire up there," said Verna Colvin, whose family owns a cabin. "It won't be the same if it burns up. It's like my life is going."
Elsewhere in Arizona, the threat posed to the city of Payson by an 84,300-acre wildfire eased after crews reinforced their fire lines near the forest community. The US Forest Service also sent a tanker plane to help fight that blaze. The planes, former Navy P-3 Orions, arrived Sunday, after officials said the aircraft's private operator had shown they are safe to fly, said Ken Frederick, a fire information officer.
In Alaska, an evacuation order remained in effect for 277 homes and businesses threatened by a blaze some 30 miles north of Fairbanks.