Three Supermoons in a Row   
       
   July 10, 2014: In June of last year, a full Moon made headlines.  The news   
   media called it a "supermoon" because it was 14% bigger and 30% brighter than   
   other full Moons of 2013.   Around the world, people went outside to marvel at   
   its luminosity.   
       
   If you thought one supermoon was bright, how about three..? The full Moons of   
   summer 2014-July 12th, August 10th, and Sept. 9th--will all be supermoons.   
       
   http://youtu.be/D1KKpeW231Y   
       
   A new ScienceCast video counts the supermoons of summer 2014. Play it   
       
   The scientific term for the phenomenon is "perigee moon." Full Moons vary in   
   size because of the oval shape of the Moon's orbit. The Moon follows an   
   elliptical path around Earth with one side ("perigee") about 50,000 km closer   
   than the other ("apogee").  Full Moons that occur on the perigee side of the   
   Moon's orbit seem extra big and bright.   
       
   This coincidence happens three times in 2014.  On July 12th and Sept 9th the   
   Moon becomes full on the same day as perigee.  On August 10th it becomes full   
   during the same hour as perigee-arguably making it an extra-super Moon."   
       
   It might seem that such a sequence must be rare. Not so, says Geoff Chester of   
   the US Naval Observatory.   
       
   "Generally speaking, full Moons occur near perigee every 13 months and 18   
   days, so it's not all that unusual," he says. "In fact, just last year there   
   were three perigee Moons in a row, but only one was widely reported."   
       
   In practice, it's not always easy to tell the difference between a supermoon   
   and an ordinary full Moon. A 30% difference in brightness can easily be masked   
   by clouds and haze.  Also, there are no rulers floating in the sky to measure   
   lunar diameters. Hanging high overhead with no reference points to provide a   
   sense of scale, one full Moon looks about the same size as any other.   
       
   Chester expects most reports of giant Moons this summer to be ... illusory.   
       
   http://tinyurl.com/ojq9gaa   
       
   Perigee is the point in the Moon's elliptical orbit closest to Earth.   
   Diagrams:#1, #2 "The `Moon Illusion'  is probably what will make people   
   remember this coming set of Full Moons, more than the actual view of the Moon   
   itself," he says.   
       
   The illusion occurs when the Moon is near the horizon.  For reasons not fully   
   understood by astronomers or psychologists, low-hanging Moons look unnaturally   
   large when they beam through trees, buildings and other foreground objects.   
   When the Moon illusion amplifies a perigee Moon, the swollen orb rising in the   
   east at sunset can seem super indeed.   
       
   "I guarantee that some folks will think it's the biggest Moon they've ever   
   seen if they catch it rising over a distant horizon, because the media will   
   have told them to pay attention to this particular one," says Chester.   
       
   "There's a part of me that wishes that this 'super-Moon' moniker would just   
   dry up and blow away, like the 'Blood-Moon' that accompanied the most recent   
   lunar eclipse, because it tends to promulgate a lot of mis-information,"   
   admits Chester. "However, if it gets people out and looking at the night sky   
   and maybe hooks them into astronomy, then it's a good thing."   
       
   Indeed it is.   
       
   Mark your calendar--July 12th, August 10th, and Sept. 9th -and enjoy the   
   super-moonlight.   
       
   Credits:   
   Author: Dr. Tony Phillips | Production editor: Dr. Tony Phillips | Credit:   
   Science@NASA   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.99   
    * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)