Sunday, May 6, 2012

Full "Super" Moon over San Francisco

“According to U.S. clocks, May 5, 2012 features the closest and largest full moon of this year. Astronomers call this sort of close full moon a perigee full moon. The word perigee describes the moon’s closest point to Earth for a given month. But last year, when the closest and largest full moon occurred on March 19, 2011, many used a term astromers had never heard: supermoon. We’ve heard this term again at this 2012 close full moon. What does it mean exactly? And how special is the May 5, 2012 supermoon?

At perigee, the moon lies only 356,955 kilometers (221,802 miles) away. Later this month, on May 19, the moon will swing out to apogee – its farthest point for the month – at 406,448 kilometers (252,555 miles) distant. So you can see tonight’s moon really is at its closest.

The supermoon of March 19, 2011 (right), compared to an average moon of December 20, 2010 (left). Will you be able to notice with your eye alone that tonight's full moon is bigger or brighter than usual? Astronomers say no, but it'll be fun to stand outside under tonight's full moon and know the moon is closer than it has been since March 19, 2011. Image Credit: Marco Langbroek, the Netherlands, via Wikimedia Commons.

How often is the moon in perigee?  The time period between the perigee moon is equal to about 1 year, 1 month, and 18 days. The full moon and perigee will realign again on June 23, 2013, because the 14th full moon after today’s full moon will fall on that date. Closest full moons recur in cycles of 14 lunar (synodic) months:

Moon closest to Earth

March 19
356,575 km
May 6
356,955 km
June 23
356,991 km
August 10
356,896 km
September 28
356,877 km

Will the tides be higher than usual? Yes, all full moons bring higher-than-usual tides, and perigee full moons bring the highest (and lowest) tides of all. Each month, on the day of the full moon, the moon, Earth and sun are aligned, with Earth in between. This line up creates wide-ranging tides, known as spring tides. High spring tides climb up especially high, and on the same day low tides plunge especially low.”

So much for the background of the ‘supermoon’.

Well, together with many photographers, I decided to go up to San Francisco in search of a good viewing point to experience the closest moon.  Thanks for Steven Christenson of Star Circle Academy [], I had a couple of places where I could view the moon rising over the Bay Bridge and choose the closest on Pier 7 at the City Waterfront.  

I explored Coit Tower as well since the elevation might offer a better vintage point but the vegetation around Telegraph Hill is too dense to have a clear view of the bridge.  Back on Pier 7 as the time of moon rise approached, photographers geared with tripods and cameras gathered at Pier 7 to watch the show.  At 8pm very shortly before the moon rise, the San Francisco Bell – a Hornblower dinner cruise – left its mooring on Pier 5 and we were all concerned whether the big slow-moving shuffle boat would block the view just when we were expecting the moon to rise.  
Coit Tower from Pier 7 later that evening.

Well, it did not happen and the Belle was out of view before the moon appeared over the horizon.  The next 1 hour  you could hear the clicking of camera shutters continuously and it was truly a bright sight to see.  It always amazes me how fast the moon rises over the horizon and I observed it traversing behind the Baybridge and almost filling the space between the span and the cables.  

Sailing the Bay under a full moon

Hornblower cruise ship under the Bay Bridge

Coit Tower from Pier 7

Later, the lights on the city waterfront started to illuminate the water with beautiful reflections and I couldn’t resist creating the night panoramas below.  

Night Panorama at the Waterfront

I hope you had a chance to go out and look up to the full moon.  It was a beautiful, unusual warm and balmy night and the City presented itself at its best.

Til next Time,


Spring has come and the Hummingbirds in the Santa Cruz Mountains are out in full.  Please join Judy and me for the upcoming Hummingbirds Photo Workshop [click for more information].

Hummingbird Photo Workshops

June 3, 2012 (1st level)
July 22 (advanced)
September 16 (1st level)   and   23 (advanced)

Instructors:  Meggi Raeder and Judy Bingman