Wildfires and Observatories

The scoop: As the Station Fire rages through the Gabriel Mountains in LA County, Ian O'Neill manages to have a chat with Scott Kardel, astronomer and public affairs coordinator at Palomar Observatory, north of San Diego, CA. Scott also runs the Palomar Skies blog.

The Station Fire is currently bearing down on the world famous Mt. Wilson Observatory (as of August 31) and there's some concern that the historic observatory may sustain some damage. Scott Kardel has some previous experience of dealing with the Californian wildfires, so he gives us a unique perspective as an employee of, and resident near, another famous observatory only 60 miles south of Mt. Wilson...

Ian O'Neill: Hi there Scott, I think it's working my end now :)

Scott Kardel: Yes, indeed.

Ian: Great!

As I mentioned on the phone, I chatted to Mike Brown who is currently watching the events unfold over at Mt. Wilson, and he mentioned you had some experience with wildfires at Palomar in 2007. How big was that fire? And was the observatory at risk?

Scott: It was called the Poomacha Fire and it burned around 50,000 acres. The fire never made it directly to the grounds of Palomar Observatory but it certainly got close and looked very threatening.

Scott: See: [image]

Ian: Wow, that plume is becoming all too familiar around here these days.

Scott: Yes, it is a very scary sight! Here is another photo taken a few days later: [image]

Ian: That's an amazing view. So what caused the Poomacha Fire? Was it arson or natural?

Scott: The exact cause is thought to have been a house fire caused by power lines that were knocked down in the 60+mph winds.

Ian: Ah yes, those Santa Ana winds have caused all sorts of problems up here in the San Fernando Valley in the past.

As I mentioned when we chatted, Discovery Space is doing a "Wide Angle" all about "Extreme Observatories" -- it was by pure chance that these fires hit this weekend.

Why are observatories such as Palomar and Mt. Wilson located in wildfire hotspots?

Scott: Of course all of the newer observatories (Keck, VLT, etc.) are in even more extreme sites, so extreme that they are above any trees, etc. But back in the time when Mt. Wilson and then Palomar were built they were considered to be very remote back country sites.

They were chosen for clear skies, good seeing, dark skies and to be remote, but not so remote that astronomers couldn't travel to and from the mountains.

With the prolonged periods of drought in So Cal, and the absence of any recent big fires the fire dangers have been very high. Even with our burn at Palomar almost 2 years ago, we have parts of the mountain that have not burned in 100 years, making the fire danger still quite high.

Ian: So do you think the fire risk to So Cal observatories is going to increase? I also heard the Mt. Wilson fire is being fueled by vegetation that hasn't burned for 60 years!

This is worrying if astronomers are going to be threatened by annual fires.

Scott: If drought continues the risk will continue to be high, but the good news here is that around Palomar there has been a program of cutting back, thinning and clearing to keep telescopes safe. But even distant wildfires are a threat to observing. The Station Fire is no where near Palomar but we have been getting ash fall here. That has kept our domes closed since early Thursday night. It is very sad to have clear skies and closed domes. But ash does not sit well with the thin aluminum reflective coating on mirrors. When combined with a bit of moisture it can form a mild acid and etch off the aluminum!

Ian: Really?! Wow, I didn't think the Station Fire was affecting you guys. You're near San Diego aren't you?