Monday, November 05, 2007

Blue Lightning (Green Ray?)

I was sitting on the couch tonight, chatting with my parents about earthquakes and strange behaviors of cows (more on that later) when I was startled by a small and then larger, bright flash of blue-green light coming from west of the Golden Gate Bridge. My first impression was that it was lightning, except there was no thunder, the color was wrong, and it was too low in the sky and without the usual bolt of light seen with lightning. Hmm, well perhaps it was an explosion? But I heard no explosion, and haven't heard about any explosions on the news here. Okay, maybe fireworks? But what is the occasion? And it was 2 quick, isolated flashes, not resembling the normal appearance of fireworks. I posted a listing on the local news section of craigslist asking if anyone else saw it, and have had 2 responses so far. One guy suggested that it could be a green flash, which is a meteorological phenomenon typically occurring right after sunset. It seemed like a possibility because of the foggy, cloudy conditions tonight, but it was 2 hours after sunset, and green flashes typically occur right as the sun sets, or soon after.

I emailed an astronomy professor in London who wrote an article on green flashes. I hope he might have some insight. Perhaps it was a green ray?

Here's the basic info.
I saw it around 7:10 PM on November 5, 2007.
It appeared near or to the west of the Golden Gate Bridge, north and slightly west of where I viewed it in the approximate center of San Francisco. I would estimate the distance at about 5 miles.
It appeared to come from the same elevation as the Golden Gate Bridge, or a little lower. It appeared to originate from below and flash up, brightening the sky. I believe there was a smaller flash before the larger, brighter flash. The bigger flash was only a few seconds long at most.

I suspect some transformer could have exploded, or perhaps it originated from a ship on the Bay. But I really don't know. I find Roswell and the X-Files amusing but don't really buy into that stuff, so I'm looking for a more plausible explanation.

Did you see it?

So thanks to my friend Sarang, the mystery has been solved. According to the San Francisco Chronicle, a plastic balloon flew into some power lines on 2nd and Clement, causing them to spark and resulting in a power outage. Who knew a balloon could cause something like that? Here's a great youtube video of a branch falling on some power lines. These guys were lucky:

Thanks also to the two astronomy professors who humored my requests and wrote me back explaining that it could not be a green flash so long after sunset. Dr. Andy Young from SDSU was closest to solving the puzzle. He said,

"It certainly sounds to me like electrical sparks between copper conductors. Are there any trolley lines in that direction?. . . Arcs between copper wires can also be caused by falling tree limbs, large birds, etc. -- though of course wires rubbing against something they normally wouldn't can also happen in high-wind conditions."

And I particularly enjoyed the email from Dr. Mike Dworetsky, Director of the London Observatory in London, UK, who enlightened me on green flashes, cloud-to-cloud lightning, and sprites. In the end he offered my favorite explanation:

"Hmmm. Nov 5th: It's Guy Fawkes night in England, traditionally celebrated with fireworks, so maybe a long-shot guess is that a British ship was letting off fireworks at sea...or maybe a British family on the Marin peninsula or at Drake's Bay?"

I'd like to see if there was a Union Jack on that balloon!


Anne said...

Okay, so a green flash has definitely been ruled out, and it doesn't seem like it could be an electrical arc due to the location and color. But a friend of mine suggested that it could be a flare from a ship. This seems like a possibility, since it was foggy tonight and the location seemed to be about right for a ship. I'll see if I can find some info about ships and flares.

Amylia said...

oooooooh, cool. you piqued my curiosity. let me know what you find out! hey, see if you can get a blue streak or two for diabetes day, okay? :)

sarang said...

Hi anne,

A balloon apparently blew a transformer at Clement and 2nd just after 7pm... Here's the
sfgate article

Sounds like what you saw. Too bad it wasn't something more exotic!


Anne said...

Thanks for solving the mystery, Sarang! It was perplexing. Here are a couple fun youtube videos:

Liz Findlay said...

Sounds like a convenient cover-up if you ask me..balloon, shmalloon. I'd say little green monsters from outer space for sure.

Anonymous said...

I was just searching to see what this series of bright green flashes I saw to the north this morning were when I found your blog. I was looking outside because the wind woke me and saw the sky light up an unearthly green a few times. No thunder followed. I'm in Daly City and the green flashes seemed to light up over San Francisco. I'll be searching SFGate to see if a power outage is reported or I should be expecting little green men.

Anonymous said...

Well no little green men. 1.2 Million people in the Bay Area have been without power at least at some point during the day according to SFGate so all the evidence points to tranformers popping off this morning.

Anne said...

Here's a cute little graphic by PGE:

The arcing I saw this morning was definitely the same color as what I saw when I originally wrote this post. I think that, when it is foggy or cloudy, the light appears brighter because it reflects off the water vapor...

Little green men would have made the morning complete. Maybe this was all a distraction planned by the little green men to take over San Francisco.

Anonymous said...

A simmilar thing occured to me. I was sitting in my livingroom, watching the snow fall at about 7:00 in the morning. Suddenly, all the lights in our house went out, presumebly a power outage, but a short few seconds later i was startled by a bright green flash comming in the window from outside. Only seconds following this the power came back on. I live in a rural area, and there are no major power lines nearby. i am posting only shortl after this event, as i came across this story as i investigeted what i saw on the internet.

ainaru said...

i also saw a green flash that occurred twice in the same area..and around .5 sec apart.

at first, i thought it was a green lighting without a thunder. but it's pretty close to the's more like a light from the ground that is being reflected unto the clouds.

oh yeah, we're having a thundershowers in carson, ca right now and the wind is about 6mph.

Anonymous said...

i saw something similar just last week, i was working and i happened to look at the clouds and i saw two bright bluish green flashes,and no thunder. i though it was fireworks but there was no trail of one, or any noise. and my though was maybe it's just lightning inside the cloud itself, especially cause the flashes came from within the cloud, and not fro the ground. it was pretty odd.