Director Returns to Mount Wilson Observatory as Fire Danger Diminishes

Astronomers came closer than they realized to losing the historic Mount Wilson Observatory on Monday, when the Station wildfire appeared to be climbing the peak along two separate fronts and fire crews had to be ordered to leave for their own safety. But a change in the weather that same day allowed firefighters to return in force on Tuesday, according to a compelling account pieced together by the Los Angeles Times.

The century-old observatory, the site of several textbooks’ worth of discoveries by astronomers and astrophysicists, is home to two big optical instruments, including the 100-inch Hooker telescope, as well as a variety of other research equipment, much of it still in use by scholars from Georgia State University, the University of California’s Berkeley and Los Angeles campuses, and the University of Southern California. Also on the mountaintop are nearly two dozen broadcast and communications towers used by television and radio stations, emergency-services providers, and others.

Some 150 firefighters cleared brush around the observatory Tuesday afternoon, in part by setting fires themselves, and sprayed structures with fire-retardant gel. Meanwhile the observatory’s director—Harold A. McAlister, an astronomy professor at Georgia State—tried to keep astronomers and others informed by watching a UCLA Webcam mounted on a tower on the site, monitoring news accounts, and then posting what little he knew to his blog. As aircraft were called in to drop water and fire retardant to stop the advance of the fire, the largest in Southern California in modern times, three of the observatory’s maintenance-staff members were asked to return to the site to help firefighters protect it.

Even so, according to the Times account, firefighters expected the blaze to reach the top of the mountain sometime Tuesday night or Wednesday morning, but it never did. By late Wednesday, fire officials said the danger was not entirely past, but they have arranged for Mr. McAlister and his wife to visit the mountain today, and Mr. McAlister said he hoped to spend the night there, in a cottage originally constructed by the Dutch astronomer Jacobus Kapteyn when he visited the observatory in the early 1900s.