Southern Arizona’s dry air, dark skies, and plentiful mountain peaks are prime conditions for the many world-class telescopes that dot the region.

These conditions, unfortunately, come with consequences. Arizona summers bring heat and lightning, the perfect storm for raging wildfires.

Telescopes perched on Mount Graham, Mount Lemmon, Mount Bigelow, Kitt Peak and on Mount Hopkins were all at least potentially threatened during this season’s wave of wildfires.

Despite some close calls, including one fire that came within several feet of a telescope, officials said the equipment escaped largely unharmed by the dangerous fires.

Mount Graham

The Frye Fire near Safford was this season’s most destructive, burning more than 48,000 acres. It is still burning in some places but firefighters have the blaze 98 percent contained.

It ignited June 7 and grew to almost 11,000 acres by June 16, growing 4,000 acres overnight. “We knew now we were going to be in harm’s way,” said Eric Buckley, director of the Mount Graham International Observatory.

By June 18 the fire (in a combination of wildfire and back burn) surged within 50 feet of the Vatican Advanced Technology Telescope in which the University of Arizona is a partner, said Buckley and Heidi Schewel, a U.S. Forest Service public affairs officer.

Also threatened by flames on Mount Graham were the Submillimeter Telescope and the Large Binocular Telescope Observatory, one of the most powerful telescopes in the world.

When the light from each of the LBT’s 8.4-meter mirrors are combined, it can produce images with the spatial resolution of a 24-meter mirror — higher than any ground-based telescope and 10 times the spatial resolution of the Hubble Space Telescope, said Buell Jannuzi, director of Steward Observatory which oversees many telescopes in Southern Arizona.

Firefighters battled the flames by back-burning the forest and dousing the area with water and slurry.

All firefighters, telescopes, and observatory personnel emerged from the fire unscathed, but astronomers did lose weeks of observing nights, Jannuzi said.

Photos of the site show a large swath of charred forest and a thin line of green trees standing around the telescopes.

“I’m just amazed we didn’t suffer any real damage,” Buckley said.

“It was not until the monsoons kicked in that we stopped really worrying about the Burro Fire and Frye Fire,” Jannuzi said.

The problem now is the lack of vegetation left on Mount Graham which leads to erosion of the soil and ash when it rains, resulting in mud slides that can block roads to the observatories.

Mount Lemmon
and Mount Bigelow

Telescopes in the Santa Catalina Mountains including the Mount Lemmon Sky Center and the 61-inch Kuiper Telescope on Mount Bigelow were closed after the Burro Fire erupted June 30.

The fire, about 2½ miles away from Mount Bigelow, prompted an evacuation of the mountain late July 3 and early July 4, and a closure of the telescopes, said Jim Grantham, head of mountain operations on both Bigelow and Lemmon.

Again, no telescopes were damaged, not even by smoke.

“I was very satisfied with the cooperation of the incident management team with me, with the observatory, in making the preparations we deemed appropriate for the Bigelow Observatory,” Grantham said.

The fire burned through more than 27,000 acres of forest, but is now 100 percent contained.

Kitt Peak

The human-caused Elk Horn Fire burned about seven miles south of Kitt Peak National Observatory, consumed 650 acres and is now extinguished.

Kitt Peak, southwest of Tucson, was closed to the public between July 6 and 10 because of the fire, but was never fully evacuated. Astronomers stayed on the mountain during the closure.

“No observing was actually affected by the fire, which was surprising,” said Lori Allen, director of Kitt Peak National Observatory. “We got very lucky with this fire because the wind never drove it to the observatory.”

When the fire broke out, Tohono O’odham fire management officer Guy Acuña called in firefighters and acted as a liaison between them and the mountain operations personnel on Kitt Peak.

“The whole southwest regional firefighting infrastructure worked very well for us, because, you remember, they were battling very large fires in more densely populated areas at the same time,” Allen said. “Yet they still managed to divert resources enough to stop this fire.”

Mount Hopkins

Lightning sparked a small fire on the west side of Mount Wrightson on July 2. The fire lasted just two days.

“We were watching it because if it grew, it could have potentially threatened (the Fred Lawrence) Whipple (Observatory) on Mount Hopkins,” Jannuzi said.

“There’s a lot of fuel on Mount Wrightson,” said Grant Williams, director of the Multiple Mirror Telescope on Mount Hopkins.

The fire was discovered and reported on Sunday afternoon, Williams said. “It was too late for the firefighters to come in and do drops from a helicopter, so it waited until the next day.”

“Fortunately it was low wind that night and few raindrops fell,” Williams said. “They came in the next day with helicopter and did seven water drops. It completely extinguished the fire.”

Another fire started a week later on the east side of Mount Wrightson during a storm, and the rain extinguished it right away.

After a tense wildfire season, the danger has largely passed thanks to an active monsoon, and no telescopes are currently threatened by fire.

Contact Mikayla Mace at mmace@tucson.com or (520) 573-4158. On Twitter: @mikaylagram.