Update, Tuesday, Sept. 8th: Mount Wilson Observatory and the nearby transmission towers have been spared, though vigilant firefighters remain on-site. Details are here.

Update, 2:00 p.m. PDT Thursday, Sept. 3rd: Progress has been made controlling the fire overall; it's now 38% contained after burning more than 225 square miles of the mountainous national forest.

Six miles away, the amateur-built Stony Ridge Observatory with its 30-inch telescope seems to have survived so far.

Update, 11:30 a.m. PDT Wednesday, Sept. 2nd: Mike Simmons writes: "The observatory is still threatened but will certainly be saved due to great preparations over the last few days and the stand the firefighters are making. While nothing is ever guaranteed in fires like this. . . the situation is about as good as it can be with flames advancing on the observatory. We are all quite optimistic."

Update, 5:40 p.m. PDT Tuesday, Sept. 1st: The Los Angeles Times reports: "Firefighters were frantically trying to save the historic astronomical observatory and dozens of critical TV and radio antennas from destruction. By 3 p.m., the fire was approaching closer than ever from two directions: one-half mile to the north and three-quarters of a mile to the west.

“ 'We expect the fire to hit the Mt. Wilson facilities between 5 p.m. today and 2 a.m. Wednesday morning,' said Los Angeles County Fire Department Deputy Chief James Powers. 'Right now, we’re conducting controlled burns around the perimeter in preparation for the impending fire's arrival. We’re also bringing in trucks and special equipment to coat all of the structures with protective gel and foam if necessary.'

". . .As he spoke from his temporary headquarters in the observatory’s main office, myriad controlled burns set beneath canyon oaks and old cedars cloaked the mountaintop with dense acrid smoke. . . .

"Chainsaws could be heard in every direction in the surrounding forest. Massive earth movers were being unloaded off flatbed trucks nearby. Powers said authorities had deliberately delayed diverting firefighters and equipment to the scene until the complex was in imminent danger.

“ 'That time is now,' Powers said. Los Angeles County Fire Department Battalion Chief Steve Martin said, 'We are going to burn, cut, foam and gel. And if that doesn’t work, we’re going to pray. This place is worth a lot, but it’s not worth dying for.' ”

Observatory director Hal McAlister, after talking with Powers, is very confident that the observatory will be saved; see his relocated fire blog. There are 150 firefighters onsite, along with observatory personnel, with no plans to leave.

Update, 2:10 p.m. PDT Tuesday: The TV footage going around the internet of smoke billowing up from around the observatory domes is merely from backfires (controlled burns to consume flammable brush) being set by the truckloads of firefighters who returned this morning to Mount Wilson's summit.

Control fires atop Mount Wilson

This picture is good news — a sign that the fire crews who have reoccupied Mount Wilson are setting controlled backfires to burn off flammable material on the observatory grounds.


Those backfires were augmented by multiple drops of water — 7,200 gallons at a time — by a Martin Mars "Super Scooper" aircraft. All this, as well as additional brush clearing by the fire crews, is in anticipation of the wildfire's arrival at the summit sometime this evening or early Wednesday morning.

Unfortunately, visual updates from the hardy webcam mounted on the observatory's 150-foot-tall Solar Tower have ceased, likely due to a backfire taking out the line from the facility's web server. The final image came at 1:49:06 p.m. PDT.

Update, 10:20 a.m. PDT Tuesday: Some good news from observatory superintendent Dave Jurasevich, who writes: "I just got off the phone with USFS Fire Dispatch at 9:40 a.m. PDT this morning. I was informed that fire crews have been reestablished on the ground at Mount Wilson to defend the observatory. If the fire continues to burn toward Mount Wilson in the direction it has been burning and does not significantly change direction, we are looking good.”

Observatory director Hal McAlister adds, "The humidity is up and the temperature is a bit lower, so, all in all, things are looking more promising than they have in the last few days."

Update, 7:00 a.m. PDT, Tuesday: Despite the loss of the summit's primary power line, Mount Wilson's webcam is still working, and its westward view at dawn shows standing trees and lots of smoke — but no flame — as shown below.

Wildfire atop Mount Wilson

Dense smoke covers the summit of Mount Wilson in this westward-looking webcam image taken at 6:51 a.m. PDT on September 1, 2009.

UCLA Dept. of Physics and Astronomy

Yesterday fire officials blanketed the area with aerial drops of fire-retardant chemicals, a move designed to let the fire burn around the historic observatory and the nearby farm of transmission towers.

Overall, the Station Fire now encompasses 190 square miles (490 km² or 121,000 acres) and has destroyed at least 53 homes. It remains only 5% contained. Officials say full containment may not be possible until September 15th.

Update, 7:10 p.m. PDT Monday: The summit webcam, the only "observer" remaining on the deserted Mt. Wilson peak, shows lots of smoke but no flame. Fire crews have been evacuated not only from the summit but also from the nearest staging area, about 5 miles away, due to danger of being surrounded and cut off.

Update, 11:15 a.m. PDT Monday: The Los Angeles Times reports:
"Crews battling the Station Fire believe that it's only a matter of time before the deadly blaze hits Mt. Wilson, but officials are hopeful that frantic work by hand crews and aircraft dropping flame retardant will protect the communications centers there.

" 'There is a good chance the fire will hit Mt. Wilson today,' said Ray Dombroski, spokesperson for the U.S. Forest Service. 'The fire is currently on two sides of Mt. Wilson, about one-half mile to the north and about one mile southwest.'

Update, 11 a.m. PDT Monday: Mike Simmons writes to us:
"I was surprised and delighted when I got up this morning to find that Mt. Wilson had not been overrun by the fire during the night. The fire has almost doubled in size during the night but it seems it has not proceeded along the last mile of the ridge to Mt. Wilson. The firefighters have been withdrawn from the observatory grounds. Presumably they have also been withdrawn from the communications facilities, which are the highest priority since they include broadcast facilities for most area TV and radio as well as cell phones and various other types.

"Today will likely be the crux. The observatory has been prepared with fire retardant dropped from planes and sprayed on structures. The tree thinning of the last few years will pay off, and some emergency brush clearing was done by the crews over the last couple days."

Update, 9:10 a.m. PDT Monday: Observatory superintendant Dave Jurasevich writes to us:

"I was able to get back up to the Observatory [Sunday] by hitching a ride on a Fire Department helicopter and we were able to ready all of our infrastructure systems for the upcoming burn. At 7:30 a.m. [Monday] morning all of the firefighters were ordered off Mount Wilson because of the imminent danger, so we were also asked to leave rather than shelter-in-place in the 100-inch dome. . . . The Mount Wilson Observatory is now in the hands of the big air tankers and God. I’m really heartbroken."

Wildfire atop Mount Wilson

The severity of Southern California's Station Fire is evident in this 2-hour sequence of images recorded Sunday evening, August 30th, by a webcam at Mount Wilson Observatory. Click here for a larger view.

UCLA Dept. of Physics and Astronomy

Original posting (Sunday Aug. 30, 2009): Right now a tense and terrifying drama is playing out in the San Gabriel Mountains, which mark the northern rim of the Los Angeles Basin. What started as a modest forest fire along the Angeles Crest Highway on the afternoon of August 26th has become a rampaging, out-of-control conflagration that is only 5% contained. So far it has engulfed some 135 square miles (345 km²) and forced the evacuation of nearly 7,000 homes.

But that's not all — by late Sunday the "Station Fire" had moved to within 2 miles of Mount Wilson Observatory, and it threatens to overrun not only the historic telescopes there, and the cutting-edge CHARA interferometric array, but also a dense crowd of television and radio transmitters and other key communications links at the summit.

For the past two days I've been watching the automated webcam located on the observatory's 150-foot-tall solar tower. The webcam happens to point westward, the direction from which the flames are advancing. Images from Sunday night, sequenced above, show the fire's ferocity in the adjacent canyons. (Heavy demand has made the webcam site almost inaccessible as of Monday.)

Sunday morning I reached observatory director Harold McAlister, who (along with his staff) spent a sleepless night after a forced evacuation. "All indications are that the U.S. Forest Service and California Division of Forestry are pulling out all the stops on fighting the Station Fire," he said. "I understand there are some 80 firefighters and 10 trucks along with a Hotshot crew of Native Americans from Arizona stationed on site to defend the observatory" and the broadcast towers next to it.

Despite some optimism Sunday afternoon that the major outbreaks weren't in the summit's immediate vicinity, a Los Angeles Times report stated that fire officials expected the summit to be overrun Sunday evening or early Monday. The U.S. Forest service decided to keep its fire crew in place at the summit overnight — "a critical aspect to the survivability of the observatory should the fire sweep across it," McAlister explains.

Throughout Sunday crews cleared tinder-dry brush from around the complex and treated wooden structures to make them less vulnerable. On his fire blog, McAlister said that he made on-site housing available for them to take showers and rest. "These are extraordinary people who say they are just doing their job," he writes, "whereas to us they are preparing to save a world-class observatory.

Mount Wilson's 100-inch telescope

The 100-inch Hooker Telescope on Mount Wilson was the largest in the world from 1917 to 1948.

Mount Wilson Observatory

Located at an altitude of 5,700 feet (1,740 m), Mount Wilson Observatory got its start in 1904 when George Ellery Hale signed a free, 99-year lease for 40 acres at the summit to build world-class telescopes. Then Hale erected the Snow Solar Telescope (1905), a 60-inch reflector (the world's largest when completed in 1908), the 150-foot Solar Tower, and finally the 100-inch Hooker Telescope (1918).

Despite being swamped with light pollution from the 13 million residents to its immediate south and southeast, the observatory has regained much of its scientific relevance. In recent years, Mount Wilson has served as a testbed for adaptive-optics and interferometric imaging. It's the main facility of Georgia State University's Center for High Angular Resolution Astronomy (CHARA) and the site of the University of California's Infrared Spatial Interferometer (ISI).

Over the weekend (and Monday as well) the Station Fire has also kept NASA's Jet Propulsion Laboratory closed to all noncritical personnel. Officially JPL is in Pasadena, California, but technically it's in the town of La Cañada Flintridge, which has been posting hourly updates about the rapidly spreading inferno. JPL is not considered in danger; its shutdown was due to the air quality. Among the activities suspended as a result was the operation of the Spirit rover on Mars.

The siting of observatories on remote mountaintops places them at great risk from forest fires, especially where climates have turned dryer in the last decade or two. In November 2007 the Poomacha Fire came near, but did not damage, Palomar Observatory east of San Diego. Likewise the University of Arizona's Steward Observatory had a close call during the Aspen Fire in June 2003.

Australia's Mount Stromlo Observatory wasn't so lucky — it was totally destroyed by a wildfire in July 2003.


Image of Alan B.

Alan B.

August 30, 2009 at 8:39 pm

Clarification: No employees have been evacuated from JPL. As a precautionary measure, the Lab was closed over the weekend except for essential personnel. To ensure acceptable air quality for the health and safety of employees, JPL will be closed to all except mission-critical employees on Monday, Aug. 31.

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Matthew Ota

August 31, 2009 at 9:06 am

I worked at Mt. Wilson as a telescope operator from 1998 to 2007. One of my greatest fears was from brush files. Now it is a real threat. I hope they can prevent the fire from overrunning the facilities.

The MWO library has metal storm covers over the windows that offer some protection. The library has hundreds of books, some of which date back to 1904.

There are a number of housing units that are constructed of wood that are vulnerable. The walkway to the 100 inch is made from wood also.

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Greg Taylor

August 31, 2009 at 5:50 pm

These observatories, Mt Wilson, etc, are national treasures. They really ought to keep a couple of big (D9 or bigger) Cat dozers up there to dig a wide fire break when such a catastrophe looms. As a PHD candidate in astronomy, I may be biased, but I think that a scarred hillside is better than a melted 100-year-old observatory.

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Matthew Ota

August 31, 2009 at 9:00 pm

The 99 year lease for Mt Wilson Observatory was not free. It was $1. When the lease expired in 2007, it was renewed for an additional dollar.

Lets hope that the phoscheck does the job in keeping the domes and other structures ssfe.

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Robert Hunter

September 1, 2009 at 1:21 pm

I guess you've seen the Mt Wilson webcam. It looks pretty bad.

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September 1, 2009 at 6:10 pm

Listening to the news earlier today I was thinking "Mt. Wilson is important enough; they should be allowed to set backfires." This is definitely good news. (I think I first learned about setting backfires reading "Little House on the Prairie" some years ago.)

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Lawrence Brown

September 2, 2009 at 2:20 pm

I think everyone should stop calling this the "Station" Fire. This was just an arbitrary name given to it when it started near a forest service station. It should be called "The Great Angeles Forest Fire of 2009."

By coincidence, a gentleman who walks his dog by my house in the evenings is a key volunteer electrician on the 60-inch telescope. They told him to stay home; He was really worried!

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Jim Toohey

September 2, 2009 at 5:25 pm

Kelly and S&T—thanks for this coverage. We care very much what happens to this beautiful piece of history!

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Enrico the Great

September 3, 2009 at 11:30 pm

Hopefully this significant observatory will be saved, and if it is saved I hope that precautions are taken in the future to lower the possibilty of such a thing re occuring.

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Pete Canfield

September 5, 2009 at 7:19 am

IMHO, the area around any obervatory should be cleared of as much vegetation except what's needed to prevent mud-slides. They cost very much to construct and are world-treasures for the advances in knowledge they give us.

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Glenn Hughes

September 7, 2009 at 2:56 am

This Aussie Observatory went up in smoke in JANUARY 2003. Oh well, your Mt Wilson fire has come at the right time for my Physics class as we watch (again) the Cosmos episode where the ne'er do well Milton Humason detcts galactic red shifts and Carl Sagan emphasises the b in billions. Hope the fire is out soon..... G

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