Firefighters build defenses to protect Robert Ferguson Observatory from Glass fire

Firefighters are shoring up defensive lines to help protect the stargazing site.|

Tree branches were still smoldering on the ground about 20 yards behind Robert Ferguson Observatory on Wednesday afternoon, their moon-like ash providing blips of contrast to the blackened hillsides where firefighters had spent two days doing controlled burns.

Crews from Petaluma, Timber Cove and Santa Cruz were still canvassing the observatory and surrounding Sugarloaf Ridge State Park, searching for spot fires that could compromise the southwestern edge of the Glass fire and further threaten a span of the Mayacamas Mountains that burned three years ago during the Nuns fire.

Defensive operations to protect such endangered areas has been a focus this week for the more than 2,000 firefighters battling the 51,266-acre Glass fire, which was 2% contained Wednesday at 7:30 p.m.

Their work here in Kenwood, creating backfires to clear ground vegetation and plowing protective bulldozer lines from the facility to Bald Mountain, could potentially spare the largest observatory dedicated to public access on the West Coast — and valuable telescopes still inside.

“Hopefully the lines hold and the work we’ve done will do its part,” Cal Fire spokesman Erick Hernandez said.

Since 1996, Robert Ferguson Observatory has attracted about 15,000 people a year, making deep-space stargazing accessible in Sonoma County. As a dark sky site, the clouds of the Milky Way become visible in the summertime thanks to its distance from the city lights of Santa Rosa.

Since the pandemic closed public access to the two major telescopes inside, the observatory has been hosting constellation viewings outside in the parking lot, said George Loyer, founding president and board member. On Friday alone, about 90 people attended, he said.

The threat of fire is a familiar feeling, though. In 2017, the Nuns fire ravaged the park, burning 80% of its more than 4,000 acres. Sugarloaf Ridge State Park Manager John Roney said eight bridges, 20 retaining walls, 150 steps and about one mile of trail had to be rebuilt.

But when the Glass fire roared in from the Napa County side of the mountains Sunday night, there was no time to get the two main telescopes inside, which they were able to do in 2017, Roney said. Now a 20-inch research telescope from the University of San Francisco, which can take deep space images in 60 seconds, and a homemade 40-inch telescope that took 12 years to build, could be lost if the inferno overtakes the firebreaks.

Combined, the telescopes cost nearly $1 million, Loyer said. And to the community, losing these windows to the infinite universe above would be more than a financial blow.

“It gives you perspective that helps you transcend some of the difficulties we’re going through right now,” Loyer said. “But it also introduces some of our visitors to the world of astronomy, which some here have made a career out of.”

If conditions allow, Roney was hopeful they would get permission to return to the observatory and get the telescopes to safety. But with high temperatures and dry and windy conditions set to return Thursday, the defensive space firefighters created this week may be tested, leaving the fate of the telescopes to the whims of the universe.

“Hopefully, the fire stays out of the building,” Roney said. “Fingers crossed on that.”

You can reach Staff Writer Yousef Baig at 707-521-5390 or On Twitter @YousefBaig.

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